Fix event.charCode issue. Remove splice workaround. Improve Binding.asArrayPath.
Binding.merge().
Context.replaceState().
Callback.onKey may accept multiple keys.
Update immutable to 2.0.4. Add getMergeStrategy/getDefaultState support.
Bump version to 0.2.1. getMergeStrategy/getDefaultState, Context.replaceState, Binding.merge, Callback.onKey test coverage.
Merge branch 'master' into development