Merge branch 'release/0.4.0'
Merge branch 'release/0.4.1'
A mixin class to improve watchers declaration.
Remove observers after save is completed.
Don't register watchers for new instances.
Merge pull request #2 from marekmalek/master

A mixin class to improve watchers declaration
Bump version
Merge branch 'hotfix/0.4.2' into develop