fix issue #1251 easy way to get contextualized models
rename variable and change back the name used for model registration
add functional test mojit
add tests, break line and comments
update comments and add unit test
add issue 1251 fix entry to history file

Conflicts:
	HISTORY.md
update example apps and tests using the contextualized model

Conflicts:
	examples/developer-guide/binding_events/application.json
	examples/developer-guide/model_yql/application.json
	examples/developer-guide/unittest_model_controller/application.json
	tests/func/examples/developerguide/model_yql_descriptor.json
update usecase app and tests using contextualized model
ac.models.get will only take model's logical name
update history file
updates basing on Drew's review feedback