Remove code for cut Fortumo using.
Remove description  "Work with multiple build variant"
Update reference in README.
Merge branch 'master' into master_with_fortumo

Conflicts:
	README.md
	library/src/org/onepf/oms/OpenIabHelper.java
Add fortumo classes.
Merge remote-tracking branch 'origin/master_with_fortumo' into dev

Conflicts:
	library/src/org/onepf/oms/OpenIabHelper.java
Return Fortumo billing option.
Merge pull request #363 from RomanZhilich/return_fortumo

Return fortumo