SVY-7543 [ Form editor ] scrollbars property is not described in spec
file but hardcoded
Implemented SVY-6995: Refactor dataprovider type; move code in property
type as much as possible

Also did some fixes/enhancements here and there along the way.
Fixed a couple of regressions of SVY-6995: Refactor dataprovider type;
move code in property type as much as possible
Fixed another regression of previous SVY-6995 commits: Refactor
dataprovider type; move code in property type as much as possible
SVY-6916 add bootstrap 12-grid category to palette

Web-Compositie support (for now only for layout)
new version prepare
Implemented some review suggestions for SVY-6995 : Refactor dataprovider
type; move code in property type as much as possible
Merge remote-tracking branch 'origin/master' into SVY-7293

Conflicts:
	sablo/src/main/java/org/sablo/eventthread/WebsocketSessionEndpoints.java
moved IDirtyPropertyListener to ngclient, webcomponent/container talk
through the parent.
moved IDirtyPropertyListener to ngclient, removed wrong/test code
Merge remote-tracking branch 'origin/master' into SVY-7293