Implement localstorage fallback also if the init process fails
Add options 'storeName' and 'version' to the VanillaStorage API

* some cleanup
* update docs
build
Merge branch 'master' into gh-pages

* master:
  build
  Add options 'storeName' and 'version' to the VanillaStorage API
  Implement localstorage fallback also if the init process fails