Quick initial integration of software keyboard into KA Lite exercises.
Merge branch 'css_cleanup' into software-keyboard
Tweaks to styling for software keyboard.
Adding other mather notations.
Adding clear input field function.
Fixed "next question" displaying issue
Showing Numberpad
Only show the numberpad if it is an andriod device.
Fix some formats
Signed-off-by: wangguan59 <wangguan59@gmail.com>
Merge branch 'develop' into software-keyboard
Show up on all the devices.
Quick initial integration of software keyboard into KA Lite exercises.

Conflicts:
	kalite/distributed/templates/distributed/exercise.html
	kalite/static/js/khan-exercises/khan-exercise.js
	kalite/static/js/khan-exercises/utils/answer-types.js
Moves software-keyboard to new location.
Implements first pass of Backbone driven software keyboard.

Conflicts:
	kalite/distributed/static/css/distributed/khan-lite.css
Makes numpad appear for all applicable answer types.
Fixes on screen keyboard to only appear for Android devices.
Removes erroneously included file.
Adds modernizr.js as static library and to base.html import.
Fixes styling for keypad buttons to make not as high.
Allows toggling of keypad, with auto-toggled off if modernizr.touch is false.

Conflicts:
	kalite/distributed/static/css/distributed/khan-lite.css