Fix more 'cpo' issues in runtime files.

runtime/ftplugin/pyrex.vim

@@ -2,12 +2,14 @@
 " Language:	Pyrex
 " Maintainer:	Marco Barisione <marco.bari@people.it>
 " URL:		http://marcobari.altervista.org/pyrex_vim.html
-" Last Change:	2004 May 16
+" Last Change:	2012 May 18
 
 " Only do this when not done yet for this buffer
 if exists("b:did_ftplugin")
   finish
 endif
+let s:keepcpo= &cpo
+set cpo&vim
 
 " Behaves just like Python
 runtime! ftplugin/python.vim ftplugin/python_*.vim ftplugin/python/*.vim
@@ -20,3 +22,6 @@ if has("gui_win32") && exists("b:browsefilter")
 			\ "C++ Source Files (*.cpp *.c++)\t*.cpp;*.c++\n" .
 			\ "All Files (*.*)\t*.*\n"
 endif
+
+let &cpo = s:keepcpo
+unlet s:keepcpo