add delegated iterables
Merge pull request #12 from kevmoo/master

bump for SDK v0.6.21+3
Update version to 0.8.1
Added optional encoding parameter, unit tests for byteStreamToString()
Merge pull request #13 from cbracken/bytestream-encoder

Add optional encoding parameter to byteStreamToString()
Merge branch 'master' into delegated-iterables
move delegated stuffs to collection and add tests
Formatting. No change to test logic.
rename DelegatedList to DelegatingList
improve dartdoc
add newlines in tests
abstract getter for delegate
String utilitities
Add delegating iterable and collections.
Add BiMap.
Merge pull request #16 from cbracken/bimap

Add bi-directional map
Correct type warnings in BiMap test.
Add Cache and MapCache
Add FakeStopwatch and FakeTimer. Use them to un-flake the CountdownTimer test.
Merge pull request #21 from google/timer

Add FakeStopwatch and FakeTimer. Use them to un-flake the CountdownTimer test.