Tweaks

* Add placeholder for git username/email in .gitconfig
* Rebase .vimrc to reflect latest configs at https://github.com/fisadev/fisa-vim-config/, notably:
  * Migrate from AutoComplPop to Neocomplcache for autocompletion
  * Migrate from pyflakes to syntastic for code checking
  * Shuffle some lines around to align with fisa-vim-config (making the diff look more significant than it is)
* A few more minor adjustments