Add MD5 as new filename cache buster
Add more MD5 & multiple hosts fixes & tests

- treat QA like production
- md5 cache busting and cache in general
- multiple asset hosts support
- add tilt cache clearing for tests
Fix MD5 cache compatibility with filenames with dots (only match exact MD5)

- Updated tests accordingly
Add test for folder glob
Keep cache buster on development individual files

- ensures browsers refreshes when file changes and we have a single behavior to deal with