implemented user-voicemail disassociation
[fix] missing argument in constructor
added begin and commit in dao dissoctaion method
fix iax trunks listing
use user_voicemail instead of user_id in user_voicemail service
use user_voicemail instead of user_id in user_voicemail validator
use user_voicemail instead of user_id in user_voicemail dao
fix unicode error

by casting string and passing utf8 argument to unicode calls
was raising a UnicodeDecodeError on non-english systems
Merge branch '4770-fix-unicode-error'
add validation module for voicemails
refactor voicemail service. use voicemail validator
Merge branch 'refactor_voicemail_validation'
use interface from protocol table instead of the one from queuemember
Merge branch '4689_dissociate_user_voicemail'
use voicemail dao instead of service in user service
refactor user service, create user validator
Merge branch 'user_validation_refactor'
refactor context service, use context validator
Merge branch 'refactor_context_validation'
Merge branch 'edit_user_with_voicemail'

Conflicts:
	xivo-dao/xivo_dao/data_handler/user/services.py
	xivo-dao/xivo_dao/data_handler/user/tests/test_services.py