initial grid keyboard navigation
move grid navigation to a mixin
scroll with the keyboard navigation
don't scroll page when navigating on a grid
setting focus is doing nothing for us
scroll only when the top/bottom is reached
remove log statement
add focus function so grid focuses on selected model
move focusModel to powergrid
set grid focus so we can use keyboard without click
keybinding is no longer a mixin
remove reference
add unit test. update to work with multi-select
add unit tests for navigation w/multi-select
use IE8 valid _.indexOf method
up/down select model if none selected

spacebar emits dbclick
check for isNaN because NaN === 'number'
find mouse to focus
set tabindex on the root element
rename method and don't set focus
keep methods alphabetical