OnlineGlomService: Return report HTML rather than the LayoutGroup.

OnlineGlomService: Return report HTML rather than the LayoutGroup.

	* src/main/java/org/glom/web/client/OnlineGlomService.java:
	* src/main/java/org/glom/web/client/OnlineGlomServiceAsync.java:
	* src/main/java/org/glom/web/server/OnlineGlomServiceImpl.java:
	Change getReportLayout() to getReportHMTL() because we will not need to
	parse or render the report layout on the client side.
	* src/main/java/org/glom/web/server/ConfiguredDocument.java:
	getReportLayout(): Return the libglom LayoutGroup type because we will
	not need to convert to a shared type, because this will not be used on
	the client side.
	* src/main/java/org/glom/web/client/activity/ReportActivity.java:
	Adapted.

	Note that there is still no implementation for this.