Add ack and controlplane to brew packages

Add:
 * ack to brew package
 * controlplane to brew cask package
Split up vim config into modular files, slightly refactor vim config

Add:
 * New vim files which act as modules for the vim config
 * Vimrc code to source all the individual files

Refactor:
 * Remove some vim functions I don’t use anymore
 * Remove Multi-cursor vim plugin
 * The vim plugin comments