Better docs, backend, CSS (Pure), with statistics

Squashed commit of the following:

commit ac4880d885bdb4ee731c6a6e900d02f69f780bea
Author: Ahmed Fasih <wuzzyview@gmail.com>

    Tweaking button

commit d869c4c3b44841b50ca56424cbd8b50390a41396
Author: Ahmed Fasih <wuzzyview@gmail.com>

    Tweaking stats

commit 7c6a38adea2377650cff04136a5715adc36897a7
Author: Ahmed Fasih <wuzzyview@gmail.com>

    More CSS tweaks

commit f90ec7602aa6bfe5fefdee965bf462413ce1220c
Author: Ahmed Fasih <wuzzyview@gmail.com>

    Merge stats and answer key in HTML

commit 47b967f8c51ce36c2f0da78bf250fb26ba4ba4b2
Author: Ahmed Fasih <wuzzyview@gmail.com>

    Reordered stats

commit b17319f5b6c75bebd04e780619e410e026058103
Author: Ahmed Fasih <wuzzyview@gmail.com>

    Fiddling with colors

commit 87bc0d87348f4869f6aa38459ba336ecea7a2f2a
Author: Ahmed Fasih <wuzzyview@gmail.com>

    Bugfix: typing in the unchecked input now good

    Before we were setting the radio button when the unchecked input was
    clicked but that didn't fire the event.

commit dba5d0d9260344f03fe26c3c1080934bfe24a6b8
Author: Ahmed Fasih <wuzzyview@gmail.com>

    Skinny CSS

commit 6c8b0102734529ff0f470614a38a398123ae80f1
Author: Ahmed Fasih <wuzzyview@gmail.com>

    Stats added

commit 99f1765b61de3ca10f35ca591a5544f083a6de93
Author: Ahmed Fasih <wuzzyview@gmail.com>

    Had to use !important to override .pure-g font :(

commit 33b90277af337041ad6636e00126b39849c49f99
Author: Ahmed Fasih <wuzzyview@gmail.com>

    generateKnown wouldn't fire when radios clicked

commit 58d71f4bee2e80d6fd74b2cd2abcab4b45b14a6d
Author: Ahmed Fasih <wuzzyview@gmail.com>

    Bugfix: reducing known kanji to remove highlights

commit a4b52f217d2ff0f7832445184c65552ee0815965
Author: Ahmed Fasih <wuzzyview@gmail.com>

    More pure!

commit 83688a98b8c2ab844e78d6ffafba4f48954e1bf4
Author: Ahmed Fasih <wuzzyview@gmail.com>

    Input known kanji can be empty, no problem

commit 96c98bb1bfea207b4e054ec99475ef5fc58551b8
Author: Ahmed Fasih <wuzzyview@gmail.com>

    Pure!

commit 2e1c825fc2609bb608857faa7fd8e0e4265f18de
Author: Ahmed Fasih <wuzzyview@gmail.com>

    Documentation and code cleanup. Case-insensitive.

    Lots of cleanup!

    One enhancement: case-insentive keyword match.