Messaging API updated:

Jira issue http://jira.webinos.org/browse/API-24: Inherit from Service object
Jira Issue http://jira.webinos.org/browse/API-12: Corrections in webinos Messaging API:
- Uses enums instead of constants
- Uses DOM errors instead of WAC proprietary
- Interface MessageFilter changed to Dictionary
- Fixed arrays
Merge pull request #13 from ClaesNilsson/master

Messaging API corrections