Important changes to Plugin Outlets for Ember 2.10

[eviltrout (Robin Ward)]

This should fix it:

Raw plugin outlets not looking in RAW_TEMPLATES in v1.7.0.beta11

This commit should fix it: https://github.com/discourse/discourse/commit/7c8095294d7296f0f27d4cb4066f1555fc8c2cbc I’ve also included a test to avoid this happening again.