vim: Several tweaks to vim config

* abbreviations are moved to plugin folder so no need to load them in
  vimrc
* wrap a couple autocmd's in augroups
* template loader will now replace a few placeholders in template.
* If the terminal supports 256 colors (setting TERM=xterm-256color will
  work) it will use the mustang theme.
* Add <leader>q to clear the highlight from previous search.
* Move soalrized theme to pathogen bundle