Fix regexp pattern searching git-dir (via #4)

1. '/.git' is unnecessary under submodule directory
   ex)
   Parent repository: C:\home\dotfiles
   Submodule repository: C:\home\dotfiles\.git\modules\dotfiles\.vim\bundle\restart.vim\COMMIT_EDITMSG
   Submodule path: C:\home\dotfiles\dotfiles\.vim\bundle\restart.vim
2. Support 'noshellslash'.