win32text: give deprecation warning

Users need to migrate to the EOL extension for various reasons.

Instructions for disabling the warning will be added to the
extension's wiki page.

hgext/win32text.py

@@ -164,3 +164,7 b' def reposetup(ui, repo):'
     for name, fn in _filters.iteritems():
         repo.adddatafilter(name, fn)
 
+def extsetup(ui):
+    if ui.configbool('win32text', 'warn', True):
+        ui.warn(_("win32text is deprecated: "
+                  "http://mercurial.selenic.com/wiki/Win32TextExtension\n"))