Update Account when Sale done

Merge branch 'sale-mgmt' into develop
Update Account on Sale

Merge branch 'develop'
Arrange observer registration queue

OPEN - task 87: Create Account module 
http://github.com/DevOpsDistilled/OpERP/issues/issue/87
Impl edit() & showDetails()

OPEN - task 87: Create Account module 
http://github.com/DevOpsDistilled/OpERP/issues/issue/87
Impl ReceivedTransaction Model & Observer

OPEN - task 87: Create Account module 
http://github.com/DevOpsDistilled/OpERP/issues/issue/87
Impl delete()
Bean EntityModel for ReceivedTransaction
Load model entity on focus lost on amount
Impl save()
Load model.entity on note field focus lost
Impl delete() with account update
Correct Impl when "Edit"
Update account when delete()
Add "Pay Payment" & Impl
Add PaidTransaction Entity Model & Observer
Add PaidTransaction PaneModel & Observer
Add PaidTransaction PaneController & Impl
Add PaidTransactionPane
Minor Changes: Button Text
Add EntityController for PaidTransaction