cursors and ref created
Merge pull request #45 from vacuumlabs/polishing

Polishing
Change interface to reference
Merge pull request #47 from vacuumlabs/cursors

cursors and ref created
rename allowMissing to missingOk
remove unecesary
added new line to cursor.dart
rename Persistent to PersistentCollection
added PersistentIndexedCollection
dissoc on sets and vectors
reduce description added
new line on test/all
new line on test/cursor
new line on test
Merge pull request #44 from vacuumlabs/moriFunc

Mori func
Merge branch 'master' of github.com:vacuumlabs/persistent into structureTests

Conflicts:
	test/all.dart
minor changes to tests