Adding close button to help popup
Merge remote-tracking branch 'upstream/2.10.x' into 2.10.x

Conflicts:
	web-client/src/main/resources/apps/js/GeoNetwork/lib/GeoNetwork/util/HelpTools.js
Merge remote-tracking branch 'upstream/2.10.x' into 2.10.x
Adapt Ext.ux.form.DateTime to use moment.js and handle
many more ISO date-time formats more reliably (gco:DateTime)
changes are in Ext.ux.form.ISODateTime
Allow gco:Date to accept a subset of Y-m-d eg. Y-m or just Y-m
Merge remote-tracking branch 'upstream/2.10.x' into 2.10.x