vim-project was not working on mac

Thanks for the great project.  Sadly, it wasn't working on the mac using vim 7.3-66.  The BufEnter auto command was never triggering since it looked something like /path/to/project//* and was failing to match everything.

My fix is to change the order of operations in the full_path function to strip the trailing slash after calling resolve.  With this change, things work beautifully.