Remove support for the editorconfig executable

Some of the code lacks copyright paperwork, so let's remove it for now,
so we don't have to adapt it to the new hooks.
If/when it proves useful/necessary it'll be easy enough to re-add.

* editorconfig.el (editorconfig-exec-path, edconf-get-properties-function)
(edconf-exec-path, editorconfig-get-properties-function): Delete variables.
(editorconfig--execute-editorconfig-exec)
(editorconfig--parse-properties, editorconfig-get-properties)
(editorconfig-get-properties-from-exec): Delete functions.
(editorconfig-call-get-properties-function):
Call `editorconfig-core-get-properties-hash` directly.

lisp/editorconfig.el

@@ -64,52 +64,6 @@ coding styles between different editors and IDEs."
   :prefix "editorconfig-"
   :group 'tools)
 
-(define-obsolete-variable-alias
-  'edconf-exec-path
-  'editorconfig-exec-path
-  "0.5")
-(defcustom editorconfig-exec-path
-  "editorconfig"
-  "Path to EditorConfig executable.
-
-Used by `editorconfig--execute-editorconfig-exec'."
-  :type 'string
-  :group 'editorconfig)
-
-(define-obsolete-variable-alias
-  'edconf-get-properties-function
-  'editorconfig-get-properties-function
-  "0.5")
-(defcustom editorconfig-get-properties-function
-  'editorconfig-core-get-properties-hash
-  "A function which gets EditorConfig properties for specified file.
-
-This function will be called with one argument, full path of the target file,
-and should return a hash object containing properties, or nil if any core
-program is not available.  Keys of this hash should be symbols of properties,
-and values should be strings of their values.
-
-
-For example, if you always want to use built-in core library instead
-of any EditorConfig executable to get properties, add following to
-your init.el:
-
-  (set-variable \\='editorconfig-get-properties-function
-                #\\='editorconfig-core-get-properties-hash)
-
-Possible known values are:
-
-* `editorconfig-core-get-properties-hash' (default)
-  * Always use built-in Emacs-Lisp implementation to get properties
-* `editorconfig-get-properties'
-  * Use `editorconfig-get-properties-from-exec' when
-    `editorconfig-exec-path' executable is found, otherwise
-    use `editorconfig-core-get-properties-hash'
-* `editorconfig-get-properties-from-exec'
-  * Get properties by executing EditorConfig executable"
-  :type 'function
-  :group 'editorconfig)
-
 (define-obsolete-variable-alias
   'edconf-custom-hooks
   'editorconfig-after-apply-functions
@@ -462,76 +416,19 @@ to non-nil when FINAL-NEWLINE is true."
              (> (string-to-number length) 0))
     (setq fill-column (string-to-number length))))
 
-
-(defun editorconfig--execute-editorconfig-exec (filename)
-  "Execute EditorConfig core with FILENAME and return output."
-  (if filename
-      (with-temp-buffer
-        (let ((remote (file-remote-p filename))
-              (remote-localname (file-remote-p filename
-                                               'localname)))
-          (display-warning '(editorconfig editorconfig--execute-editorconfig-exec)
-                           (format "editorconfig--execute-editorconfig-exec: filename: %S | remote: %S | remote-localname: %S"
-                                   filename
-                                   remote
-                                   remote-localname)
-                           :debug)
-          (if remote
-              (progn
-                (cd (concat remote "/"))
-                (setq filename remote-localname))
-            (cd "/")))
-        (display-warning '(editorconfig editorconfig--execute-editorconfig-exec)
-                         (format "editorconfig--execute-editorconfig-exec: default-directory: %S | filename: %S"
-                                 default-directory
-                                 filename
-                                 )
-                         :debug)
-        (if (eq 0
-                (process-file editorconfig-exec-path nil t nil filename))
-            (buffer-string)
-          (editorconfig-error (buffer-string))))
-    ""))
-
-(defun editorconfig--parse-properties (props-string)
-  )
-
-(defun editorconfig-get-properties-from-exec (filename)
-  "Get EditorConfig properties of file FILENAME.
-
-This function uses value of `editorconfig-exec-path' to get properties."
-  (if (executable-find editorconfig-exec-path)
-      (editorconfig--parse-properties (editorconfig--execute-editorconfig-exec filename))
-    (editorconfig-error "Unable to find editorconfig executable")))
-
-(defun editorconfig-get-properties (filename)
-  "Get EditorConfig properties for file FILENAME.
-
-It calls `editorconfig-get-properties-from-exec' if
-`editorconfig-exec-path' is found, otherwise
-`editorconfig-core-get-properties-hash'."
-  (if (and (executable-find editorconfig-exec-path)
-           (not (file-remote-p filename)))
-      (editorconfig-get-properties-from-exec filename)
-    (require 'editorconfig-core)
-    (editorconfig-core-get-properties-hash filename)))
-
 (defun editorconfig-call-get-properties-function (filename)
-  "Call `editorconfig-get-properties-function' with FILENAME and return result.
+  "Call `editorconfig-core-get-properties-hash' with FILENAME and return result.
 
 This function also removes `unset' properties and calls
 `editorconfig-hack-properties-functions'."
-  (unless (functionp editorconfig-get-properties-function)
-    (editorconfig-error "Invalid editorconfig-get-properties-function value"))
   (if (stringp filename)
       (setq filename (expand-file-name filename))
     (editorconfig-error "Invalid argument: %S" filename))
   (let ((props nil))
     (condition-case err
-        (setq props (funcall editorconfig-get-properties-function
-                             filename))
+        (setq props (editorconfig-core-get-properties-hash filename))
       (error
-       (editorconfig-error "Error from editorconfig-get-properties-function: %S"
+       (editorconfig-error "Error from editorconfig-core-get-properties-hash: %S"
                            err)))
     (cl-loop for k being the hash-keys of props using (hash-values v)
              when (equal v "unset") do (remhash k props))