Tabular overhaul:

1. Fixed Error handling method
2. Reworked where errors live
3. Fixing testing (some still failing)
Test Fixes:

1. All broken Tabular tests now working
Render Tests fixes and added fixtures
Minor update to recursive importing:

Fixes uber-verbose importing of non-packages
Merge branch 'master' of https://github.com/CenterForOpenScience/modular-file-renderer