Added the option to overwrite an object in StoreInfo and save it
Ignoring uneeded files
Update changelog.md
Added documentation to billing files.
Merge branch 'master' into docs

* master:
  Update changelog.md
  Ignoring uneeded files
  Added the option to overwrite an object in StoreInfo and save it

Conflicts:
	SoomlaAndroidStore/src/com/soomla/store/data/StoreInfo.java