Forward port the fixes from 6.x which where mostly done but cleanup extra
lines added to the top of php files and some slight mistakes.

Issue #1177220 by tim.plunkett: Expand coverage of ctools_dependent_pre_render to machine_name and date fields.

Issue #1094014: Allow export $item->type to be something else to reduce namespace collisions on exportable objects.

Issue #1104132: Context selection in views panes/contexts was sometimes using wrong contexts due to entity transition.

Issue #1103278 by dereine: Add CRUD function to enable/disable objects. Update the api version to make it easy for modules to detect the presence of the new function.

Issue #1102252: Implement and document default object caching, taken mostly from how Views used to do it.