Actually, remove deps.flush render thing

It is no longer true.
Automatically remove deprecated preserve-inputs
warning about manual rendering
Add stuff about template files to spacebars README
Update concepts section
initial history.md pass
add external contributors
Check package notices line length
banner and notices rough draft
Fix stylus tests to test stylus rather than less
Remove preserve-inputs package -- an upgrader removes it from apps
Merge branch 'release-0.8.0' into devel

Conflicts:
	History.md