#35

* add angular-hotkeys to bower.json
* include angular-hotkeys module in app
* setup path and shim for angular-hotkeys module in min.’s
#35

* add up, down, left, right and enter key handler into commit list view
* set location hash to current selected commit.sha to scroll into view
#35

* add selected class to current selected commit
* add scroll target dummy
#45

* add styles for scroll dummy and selected commit in commit-list.less
#45

* import hotkey help style into main.less file