Escape # in :Glog

Closes #265.

plugin/fugitive.vim

@@ -1066,7 +1066,7 @@ function! s:Log(cmd,...)
   let dir = getcwd()
   try
     execute cd.'`=s:repo().tree()`'
-    let &grepprg = escape(call(s:repo().git_command,cmd,s:repo()),'%')
+    let &grepprg = escape(call(s:repo().git_command,cmd,s:repo()),'%#')
     let &grepformat = '%f::%m'
     exe a:cmd
   finally