Add essential data objects for tmj mesh loading

[MarkOates]

Several data objects were added during #248 that were not included in the PR or the merge. They need to be updated into master. A full list is not known (but there aren't many, tbh). Here's the ones that come to mind:

• New .tmj files in bin/data/maps/
• New .tmj fixture files in tests/test_fixtures or tests/fixtures
• Possibly some png files used for textures in either fixtures or data.
• Others not currently known