additional comma and addAll: test for overlapping Sets
ifAbsentPut: tests

Array does not have at:ifAbsentPut:, ???
Push at:ifAbsentPut: up
Tests for comma in HashedCollection, allowing comma

Pharo has comma for Dictionaries.
Update API-CHANGES.txt
Merge branch 'upstream' into at-ifabsentput-tests
Update API-CHANGES.txt
Update API-CHANGES.txt
Merge branch 'upstream' into allow-comma-for-hashedcollection
Merge pull request #785 from herby/at-ifabsentput-tests

at:ifAbsentPut: tests, additional tests for Set
Removes HLReferencesModel >> allSelectors that was slowing down
references further searches
Merge branch 'allow-comma-for-hashedcollection' of https://github.com/herby/amber into herby-allow-comma-for-hashedcollection

Conflicts:
	API-CHANGES.txt