Support getting commonAncestor for more than 2 nodes.
Fix bug in retrieving blob object in objectstore.
refactor the workspace to store workspace roots differently
Return data in right dataType in retrieving rawObject.
Add third-party diff3 js implementations.
Add dart wrapper over diff3.js.
Support non-fast-forward merges.
Add util function to get sha for a blob object.
Delay writing of objects, only when merge is successful.
remove debug messages.
Add todo.
fix an issue w/ restoring the project location
Rename files under widgets/examples ('-' -> '_')
Further file renaming
Further example fixes
Fix and expand spark-splitter example
Finish spark-split-view example
Merge pull request #980 from ussuri/update-widgets-examples

Update widgets examples
Move cleanWorkingTree function to utils.
Merge pull request #981 from dart-lang/util_func

Move cleanWorkingTree function to utils.