Updated localised strings
Added localisation for product characteristic group names
Merge branch 'develop' of https://github.com/ProductLayer/ProductLayer-SDK-for-iOS into develop
Added opines to demo app
Changed Voting function. Now all PLYVoteableEntities can be voted.
Fixed capitalization problem with GTIN
refactoring
Merge branch 'develop' of https://github.com/ProductLayer/ProductLayer-SDK-for-iOS into develop