Merge branch '21_1' of https://github.com/DevExpress/DevExtreme into … #674

Job	Run time
qunit-tests (true, google-chrome, export, jquery=3)	1m 18s
qunit-tests (true, google-chrome, misc, jquery=3)	1m 20s
qunit-tests (true, google-chrome, ui, jquery=3)	1m 12s
qunit-tests (true, google-chrome, ui.widgets, jquery=3)	1m 25s
qunit-tests (true, google-chrome, ui.editors, jquery=3)	1m 17s
qunit-tests (true, google-chrome, ui.grid, jquery=3)	1m 15s
qunit-tests (true, google-chrome, ui.scheduler, jquery=3)	1m 17s
qunit-tests (true, google-chrome, viz, jquery=3)	1m 17s
qunit-tests (true, google-chrome, renovation, jquery=3)	1m 48s
	12m 9s

Provide feedback