Use a LayoutPanel with multiple display areas for main layout.

Use a LayoutPanel with multiple display areas for main layout.

This is mostly a refactor in that there are no changes from the user
point of view. These changes are required so that we can swap out the list view
with the details view when the user clicks the "Details" button.

* src/main/java/org/glom/web/client/ClientFactory.java:
* src/main/java/org/glom/web/client/ClientFactoryImpl.java: Remove
OnlineGlomView. Add TableSelectionView, ListView and
AuthenticationPopup.
* src/main/java/org/glom/web/client/OnlineGlom.java: Use LayoutPanel
for main layout. Add display regions for main activities. Add
activity manager for for main activities.
* src/main/java/org/glom/web/client/activity/ListActivity.java: New
file from parts of the deleted OnlineGlomActivity.
* src/main/java/org/glom/web/client/activity/TableSelectionActivity.java:
New file from parts of the deleted OnlineGlomActivity.
* src/main/java/org/glom/web/client/event/TableChangeEvent.java:
* src/main/java/org/glom/web/client/event/TableChangeEventHandler.java:
New files for app wide table change event.
* src/main/java/org/glom/web/client/mvp/DataActivityMapper.java:
* src/main/java/org/glom/web/client/mvp/DocumentSelectionActivityMapper.java:
* src/main/java/org/glom/web/client/mvp/TableSelectionActivityMapper.java:
Activity mappers for the main activities replace the deleted app-wide
AppActivityMapper.
* src/main/java/org/glom/web/client/ui/AuthenticationPopup.java:
Fix a spelling error in he comment.
* src/main/java/org/glom/web/client/ui/ListView.java:
* src/main/java/org/glom/web/client/ui/ListViewImpl.java:
Renamed from LayoutListView and modified for MVP. This still not a
proper dumb view as prescribed by the MVP pattern but it works for now.
* src/main/java/org/glom/web/client/ui/TableSelectionView.java:
* src/main/java/org/glom/web/client/ui/TableSelectionViewImpl.java:
New widget stripped out of the deleted OnlineGlomView.
* src/main/java/org/glom/web/server/OnlineGlomServiceImpl.java:
Remove hack that is fixed by this patch.