documentation work-in-progress
Merge branch 'master' into unity-docs

* master:
  Fix #if directives for instantiation.
  Clearify StoreInfo implementation.
  Clearify StoreInventory implementation.
  Clearify StoreController implementation.
Added documentation.
A few small doc fixes.
Added documentation.md and added some inline docs.
fixed mistake in documentation.md
Changed license in documentation.md
Merge branch 'master' into unity-docs

* master:
  Added missing parentheses breaking Android build in StoreController.
  Fixed an issue with IABActivity in android-store
  - Added 'transactionIdentifier' as purchaseToken on iOS   fixes #216 - fetched latest changes on submodules
  (ios-store) Fixed an issue with recieptUrl not being set on iOS<7
Documentation fixes.
Update README
Documentation fix
Merge branch 'unity-docs'

* unity-docs:
  Documentation fix
  Update README
  Documentation fixes.
  Changed license in documentation.md
  fixed mistake in documentation.md
  Added documentation.md and added some inline docs.
  A few small doc fixes.
  Added documentation.
  documentation work-in-progress