Convert DOH tests to use Intern

Majority of work done by Paul Bouchon
Review and porting of remaining DOH tests by Ken Franqueiro
CHANGES.md: Add note about switch to Intern
Fix #664: Allow blank labels (specified as empty string)
Fix use of queryRowsOverlap when scrolling an OnDemandList down.
CHANGES.md: note queryRowsOverlap fix
Fix #665: Remove unreferenced modules from CompoundColumns deps list
Remove doh folder references from test index
Fix #603: editor throwing error on blur event

When the node is removed it is triggering another blur event. Fix by
Pausing the blur event before the child is removed
CHANGES.md: note editor blur fix for Chrome/Safari
ColumnSet: fix horizontal scroll glitch on Chrome at some zoom levels
Merge remote-tracking branch 'sitepen/master'
New TestCase for mixin DnD, OnDemandGrid, Selection and Keyboard. There is
a problem with IE10 and MSPointerXXX events.