Compression, refactor

* playing with LZString lib for compressing data, especially on websql as we
  store strings there and this runs on most mobile devices (ios/android)
  See http://pieroxy.net/blog/pages/lz-string/index.html
* integrate LZString to WebSQLStorage adapter for testing, unit tests still
  green, first tests showed that everything seems to work ok
* restructure tests to different files: one for the adapters in isolation,
  one fpr the vanilla frontend

NOTE:
Compression makes the app crash while running the unit tests with compression
for websql enabled (which works on commandline and other mobile devices)
on iphone4/iphone5 (both ios7.0.6)