Windows portability: fix construct in findfont.ph, README update

Fix a construct in doc/findfont.ph which crashes Perl on Windows
unconditionally.

Improve the README for building the full package with MSVC.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Mkfiles/README

@@ -13,16 +13,21 @@ The Makefiles are:
 
 	If the following tools are installed, the full installer package can
 	be built:
-		1. Perl (5.6 or later)
-		2. Nullsoft Scriptable Installer System (makensis)
+		1. Perl (5.6 or later), e.g. ActivePerl or StrawberryPerl
+		   http://strawberryperl.com/
+		2. Nullsoft Scriptable Install System (makensis)
+		   http://nsis.sourceforge.net/Download
 		3. Ghostscript (ps2pdf) or Acrobat Distriller (acrodist)
+		   https://downloads.ghostscript.com/
 		4. The Adobe Source Sans Pro and Source Code Pro fonts
-		5. The Perl module Font::TTF
-
+		   https://github.com/adobe-fonts
+		5. The Perl module Font::TTF (can usually be installed
+		   via the "CPAN Client" in your Perl distribution)
+		   http://search.cpan.org/~bhallissy/Font-TTF/
 	The tools need to be in your current path.  To build the
 	installer package, run:
 
-		nmake /f Mkfiles\msvc.mak nsis
+		nmake /f Mkfiles\msvc.mak everything nsis
 
   Filename      Target		Compiler	Tested with
   ---------------------------------------------------------------------------

doc/findfont.ph

@@ -132,10 +132,13 @@ sub findfont($) {
     }
 
     # Are we on a system that uses fontconfig?
+    # NOTE: use a single string for the command here, or this
+    # script dies horribly on Windows, even though this isn't really
+    # applicable there...
     if (!defined($file) &&
-	open(my $fh, '-|', 'fc-match',
-	     '-f', '%{file}\n%{postscriptname}\n',
-	     " : postscriptname=$fontname")) {
+	open(my $fh, '-|',
+	     "fc-match -f \"%{file}\\n%{postscriptname}\\n\" ".
+	     "\" : postscriptname=$fontname\"") {
 	chomp($file = <$fh>);
 	chomp($psname = <$fh>);
 	close($fh);