vim: files listed by `Unite_project_files` are opened in the previous window
vim: replace the mappings of open_in_previous_window as a default action with edit_in_previous_window
vim: change the buffer name of `Unite vcs_grep/git` from grep to vcs-grep-git
Revert "vim: replace the mappings of open_in_previous_window as a default action with edit_in_previous_window"

This reverts commit 0383747a84fa1b408af1a610f26c501214647a1b.

Conflicts:
	.vimrc