Remove process isolation

Tests are now failing
Some minor test edit + cleanup
Add and implement custom UnitTestCase & Factory
Add file object, load, and test
Refactor mocks into testcase for reuse
Add post object, load, and test

* File object no longer needs WP_Gistpen_Post to be created
Add language object, load, and test
Fix bug in factory
Refactor out default factory for reuse
Add query object, load, and test

Only `get`s from the database
Integrate query into content
Update test-updater with new methods
Finish docs on query
Trying to avoid touching globals
Typecast object language construct needs
Extend testcase to include AJAX
Leftover debugging functions
Remove return languages

* We'll localize the scripts instead, saves a test
Create WP_Gistpen objects from WP_Post objects
Fix broken object tests