Parcial Commit
Merge branch 'master' of https://github.com/globant/googleappengine-training

Conflicts:
	AddsIncGAE/src/com/globant/gaetraining/addsincgae/model/Campaign.java
	AddsIncGAE/src/com/globant/gaetraining/addsincgae/services/HomeService.java
Merge branch 'master' of https://github.com/globant/googleappengine-training
Add campaing_key string to Product entity. It's setting in the constructor. There are some pieces of testing code