AssetURI doesn't use errors
Move more fields to metadata
Mark write_to as deprecated
Inline process()
Extract sorted tree traversal
First pass at locate
Remove commented out test
Inline resolve_all_under_load_path
Revert "Inline resolve_all_under_load_path"

This reverts commit 81a636e933ec9f2503ec59aab130d2fff89fcb4a.
Use resolve_all_under_load_path
mtime tracking is deprecated
digest_class getter is still okay
Test find mime_type matches with parsed q values
Separate transformers tests
Check conversion when building transformer pipeline
Pass parsed accepts directly to resolve transform types
Optional accept is unused
Recorded inverted transformer hash
depend on doesn't imply any content type
Inline resolve_all