Remove unused mapping
Add mappings for easymotion line navigation

I think they might be useful enough to not have as leader-combinations.
Add vim-sensible plugin

Provides a baseline, allowing me to remove some stuff from my
settings: https://github.com/tpope/vim-sensible
Recategorize plugins

It felt like too many things were bunched up under "Utility". I have
reordered things so that "Tools" are the things that introduce new
commands/functionality, and "Utility" just tweak existing functionality.
Add gitgutter plugin

Can also be used to stage individual hunks (ala git add -p):
https://github.com/airblade/vim-gitgutter