removed Errai helloworld qs

Conflicts:
	helloworld-errai/README.md
	helloworld-errai/functional-tests/pom.xml
	helloworld-errai/pom.xml
fixed helloworld-gwt qs
Removed uses of deprecated jQueryMobile APIs.

* Replaced use of $.mobile.changePage with pagecontainer's change event.
* Replaced use of data-role="content" with ui-content class.
* Replaced use of data-role="fieldcontain" with ui-field-contain class.
* Replaced use of data-role="content" with ui-content class.
* Replaced the filter extension with the Filterable widget.

Also replaced button markup for anchor tags with CSS classes.
Upgrade to GWT 2.6.1
updated WFK and EAP BOMS to 6.2.2.GA and 2.6.0-build-1 versions
Update CONTRIBUTING.md

Correcting the fork link for DEVELOPER-410
https://issues.jboss.org/browse/WFK2-613 removed also remaining files in helloworld-errai