added new method to query subscription sku details
Merge pull request #173 from GrimReio/bug-131

added new method to query subscription sku details
Update README.md - verification on server
Fix for #144 queryIntentServices() returns null on some ROMs
Update README.md - testing on Google Play
request inapp/subs skus as single param
Merge pull request #179 from GrimReio/unity-android-sku-request

request inapp/subs skus as single param
Merge branch 'master' of https://github.com/onepf/OpenIAB
fixed amazon NPE issues