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August milestone: custom functions, trig keyboards, matrices and more
Ah I did some things and I don't know what they are
"pull-up" keyboards implemented

Dragging the main keyboard up now reveals a menu to very quickly open
other keyboards (or anything else really though app.acceptActionInput)
Fixed the random keyboard popups
Things work now, mostly

- Added history for LiveEval

- Fixed sticky inputs in GrapherListView that didn’t disappear when
empty

- Changed EVAL button to SET button, now allows for storage in
arbitrary variable

- Refactored set variable prompt to Application (still need to merge
Application and SigmaboxAppFrame)

- Canvas so smooth, wow

- Probability distributions that didn’t work now do

- Nasty bug where Frac receiving a Number rather than a Value in the
numerator/denominator fixed
Fixed the value of K_E which should be 1 / (4 * pi * e_0)
Removed console.logs
Merge branch 'master' of https://github.com/idreyn/Sigmabox