WIP tier-group prototype.
WIP.
Working prototype of tier-groups.
Merge branch 'tiergroups'

Conflicts:
	js/cbrowser.js
	test37.html
Merge branch 'tiergroups'

Conflicts:
	test37.html
Fix for DAS sequence case bug.
Inadvertant use of globals in image export.
Include sequence tracks in exported images.
Imports.
Add mismatch-all SEQUENCE style.
Support for custom sequence sources.
Option to restore "coloured letter" view of BAM reads via __CLEARBG stylesheet property.
Export DASSequence for SequenceSource plugins.
Add a noSourceCSS option.

This prevents BioDalliance from injecting <link> tags onto the page,
which is helpful if you want to avoid precedence wars and !important by
to managing CSS yourself.
Merge pull request #102 from danvk/feature

Add a noSourceCSS option.
Salt URLs before fetching sequence.
Merge branch '0.12.x'
Merge branch 'master' of github.com:dasmoth/dalliance
Use standard Array.prototype.forEach
Fix missing import.