Override the 'grin' function.

The default `grin' implementation performs the search in the current
directory. The `grin' function defined here wraps the real `grin'
asking for a directory to search from. It's a bit hackish but it
works.


git-svn-id: svn://localhost/emacslib/emacslib/trunk@449 a9598837-e506-0410-a967-fbf0066ee963