Merge pull request #1 from Xuyuanp/git-status

add git support
Merge pull request #2 from Xuyuanp/git-status

Git status
update readme
add TODO in readme
set g:nerdtree_show_git_status default value to 1
add keymap: ']c' to next hunk, '[c' to prev hunk
git status highlight without '[RO]'
Update README.markdown
Update README.markdown
Change git status detecting method
Now I use 'git status -s {path}' command checking a path's status. No longer cached the current directory's git status. It maybe take the view rendering being a little slower, but in this way, I get less code and less independence.
Merge branch 'master' of https://github.com/Xuyuanp/nerdtree

* 'master' of https://github.com/Xuyuanp/nerdtree:
  Update README.markdown
Sorry....I regret it..... It's not becoming a little slower.... very very very slow
Format function name. Refresh git status at right time