Fix #775: Fix has-css3 feature detection, especially css-transforms3d

css-transforms3d was testing using a media query which is not supported by
non-webkit browsers.  Testing using the `perspective` style property is
sufficient in all but now-ancient versions of Chrome.
CHANGES.md: Note has-css3 fixes
Add warning about not setting sort on observable stores
Test cleanup, primariy adding sort property where missing
Minor test fixes
Fix #876: editor: Reference correct column during change handling

editor sets up a single delegated event handler for native input elements,
but it was always referencing the first column that it happened to set up
the handler for.  This happened to be mostly harmless in most cases, but
caused issues particular to radio button handling.
CHANGES.md: Note editor input change event handling fix
editor functional tests: minor consistency update

(Doesn't affect outcome of tests)
ColumnHider: Extend left/right to skip hidden cells
CHANGES.md: Note ColumnHider#left/right fix
Add centralized dgrid-autoheight class
Test and adjust dgrid-autoheight for RTL
CHANGES.md: Note dgrid-autoheight class
Fix #873: Make ui- classes optional based on addUiClasses property
Rename white version of icons
CHANGES.md: Note addUiClasses property
Pagination unit test: fix missing comma, remove unused var
Fix #866: Keyboard: Don't try to restore focus if target isn't visible
CHANGES.md: Note Keyboard focus restoration error fix