Updated all plugins that are non-forked. Added some new plugins.

Added update_plugins.py which can fetch new plugins from GitHub.

New plugins added: zencoding, vim-indent-object, taglist, nginx.vim
Updated documentation
Reverted back powerline
Reverted powerline version. Increased font size
Fixed some things in peaksea (regarding omni menu and folding in terminal mode). Optimized a bit colors for powerline
Ignore docs tags
Removed generated doc tags from git repo
Added two new plugins: vim-expand-region and vim-multiple-cursors.

They are both super useful. Read more on their GitHub pages for more info:
https://github.com/terryma/vim-expand-region
https://github.com/terryma/vim-multiple-cursors
Fixed a typo in documentation
Added a new maping to update_plugins.py
Revert overriding CTRL-A (instead we use CTRL+S)
Updated vim plugins
Updated plugins
Updated plugins
Added tags (docs)
merge