First step in fixing issue https://github.com/cs150bf/ever-notedown/issues/4
First step in fixing issue https://github.com/cs150bf/ever-notedown/issues/4

Reference: http://stackoverflow.com/questions/23223718/failed-to-execute-btoa-on-window-the-string-to-be-encoded-contains-characte
Notes:
1. ... first google result...
2. Apparently it works because it's buggy?
3. Well probably not really working. Non-latin1 characters render
poorly in preview and the font-sizes are messed up in the converted
PNG...
    - e.g. test cases `$$\text{畢氏定理} a^2 + b^2 = c^2$$`, `$$\text{théorème de Pythagore} a^2 + b^2 = c^2$$`

cs150bf/ever-notedown