PEP8
Use parent's sort order (if present) in diff view
When exiting diff mode from an interp, jump to the first subterp
Link to proper subterp from search results
Account for caching between tests
Instatiate HeaderView before DrawerView
Use threads to make layer requests
Don't use SxS layer for general rendering
Improvement in update_offsets performance
Use SectionUrl to determine where to link to in SxS
Licenses in line w/ rest of CFPB
Merge pull request #652 from cmc333333/dox

Licenses in line w/ rest of CFPB
Use a single SectionUrl object in the TOC, rather than per match
Merge pull request #643 from cmc333333/diff-order

Use parent's sort order (if present) in diff view
Merge pull request #649 from cmc333333/optimize-sxs

Don't use SxS layer for general rendering
Merge pull request #651 from cmc333333/sxs-to-interp

Use SectionUrl to determine where to link to in SxS
Merge pull request #653 from cmc333333/opt-toc-urls

Use a single SectionUrl object in the TOC, rather than per match
Merge pull request #650 from cmc333333/optimize-tags

Improvement in update_offsets performance
Merge pull request #648 from cmc333333/optimize-threads

Use threads to make layer requests
Docstring for SectionUrl