update pre-built binary path for a win32 patch

Also, describe the patch in the Windows build notes.

This change increases access to symbol fonts, though not in a
completely consistent and portable way. See the closed problem
report for more information, as well as a 24-NOV-2012 post
on the Racket mailing list:
 http://lists.racket-lang.org/users/archive/2012-November/055141.html

Closes PR 13300

src/download-libs.rkt

@@ -4,7 +4,7 @@
 (provide do-download)
 
 (define url-host "download.racket-lang.org")
-(define url-path "/libs/9/")
+(define url-path "/libs/10/")
 (define url-base (string-append "http://" url-host url-path))
 (define architecture #f) ;; set in `do-download'
 

src/worksp/README

@@ -125,6 +125,14 @@ make the OpenSSL source refer to `_stat', you must use `struct
 _stat64i32' in place of `struct stat', `#undef _stat', and use
 `_stat()' in place of `stat()'.
 
+The pre-built binaries are unpatched with the exception of
+"libpangowin32", where we have disabled the SYMBOL_CHARSET test that
+makes Pango ignore symbol fonts. The test is in the
+pango_win32_insert_font() function, and the patch was made in the
+pre-built binary by modifying the machine code: change a comparison
+to 2, which is SYMBOL_CHARSET, to a comparsion to 3, which doesn't
+correspond to any CHARSET.
+
 
 Building Racket3m and GRacket3m
 -------------------------------