Implement navigation to report places.

Implement navigation to report places.

* src/main/java/org/glom/web/client/activity/ReportActivity.java
start(): Do not bother to handle all events here.
* src/main/java/org/glom/web/client/ui/TableSelectionView.java
* src/main/java/org/glom/web/client/ui/TableSelectionViewImpl.java:
Added getSelectedReport().
* src/main/java/org/glom/web/client/activity/TableSelectionActivity
.java: start(): When handling a change to the reports chooser,
call getSelectedReport() and goTo() its ReportPlace.
* src/main/java/org/glom/web/client/ui/ReportView.java
* src/main/java/org/glom/web/client/ui/ReportViewImpl.java:
Added setReportHTML() which puts the html in a gwt HTML widget.
* src/main/java/org/glom/web/server/OnlineGlomServiceImpl.java
getReportHTML(): Return TODO just to show that this works.