Remove GitGutter plugin

This was slowing down saves at random times. It was annoying enough to
warrant removal, since it's something I can live without.
Allow blank lines in plugins.list

Allows for organization of plugins if a user so chooses.
Remove magic regex search default
Remove EasyTags plugin

This wasn't being used. Kill it.
Add more Syntastic configuration settings

Add keyboard shortcuts for closing/opening location list, as well as
making working with Syntastic a bit easier, specifically with regards to
RoboCop.