Make fields in Statement private
Deprecated Entity::newClaim and Entity::getAllSnaks
Merge pull request #146 from wmde/deprecate

Deprecated Entity::newClaim and Entity::getAllSnaks
Merge pull request #144 from wmde/Statement

Make fields in Statement private
Add getClaim method to Statement

This is preparatory work for changing the relation between Claim and
Statement from inheritance to composition, as listed on
https://github.com/wmde/WikibaseDataModel/issues/22
Merge pull request #145 from wmde/getclaim

Add getClaim method to Statement
Update RELEASE-NOTES.md
Remove not used ClaimAggregate
Add getStatements to Item and deprecated getClaims
Some naming imporvements