Remove Deprecations For Ember-Data-4

[nadnoslen]

The following deprecations were introduced because now that Ember supports accessors without using the .get(...) function, we can't pollute the names with question marks (like in Ruby). I got comfortable decorating my computed property names with question marks in 2014 and now it needs to stop.

• ember-data-base-model/models/-base.deprecate-unaltered-question-mark
• ember-data-base-model/models/-base.deprecate-altered-question-mark
• ember-data-base-model/models/-base.deprecate-persisted-question-mark
• ember-data-base-model/models/-base.deprecate-new-question-mark
• ember-data-base-model/models/-base.deprecate-dirty-question-mark
• ember-data-base-model/models/-base.deprecate-clean-question-mark