.vimrc: Enable spellcheck for git commit messages
Ignore vim spell files
Merge branch 'master' of git://github.com/jrunningen/dotfiles

* 'master' of git://github.com/jrunningen/dotfiles:
  tmux: Replace old powerline unicode characters
  .vimrc: Add mapping for opening the current file in NERDTree
  .vimrc: Add mapping for syntastic errors
  Excise old powerlines, add airline
  Add vim-abolish