Updated: Experiment failed. :(

Re-activating arrow keys after more than 3 months.
Updated: Made <space> the leader key.

Insired by http://sheerun.net/2014/03/21/how-to-boost-your-vim-productivity/.
Added: Another test directory source prefix.

TODO: Should find a better way to determine these, since there are too
many variations in different projects.
Updated: Removed EasyMotion since I did not use it at all.
Updated: Removed window move bindings I did not use.
Added: Trying vim-expand-region.
Fixed: WS.
Updated: Removed another unused shortcut.
Added: Mapping and config for region expand.
Updated: VIM tips.
Updated: Remap tab navigation to allow y/p/d with system clipboard.
Updated: Also remap tab movement.