IdGenerator - tests and implementation
First implementation of ChangeSet
Collection is now using changeSet
Small fixes
Some small changes.
Other minor requested changes.

Signed-off-by: Jozef Brandys <jozef.brandys@gmail.com>
Small changes + remove in Model.
Small changes + remove in Model.
Merge
Some small changes. Tests need to be fixed.
Small changes.
Merge branch 'master' of https://github.com/brandys11/clean_data
Merge pull request #1 from brandys11/master

ChangeSet implementation