Use GWT.log for client-side debugging statements.

Use GWT.log for client-side debugging statements.

These are optimized out when deployed so I should have used this method
in the first place. These statements will eventually be replaced with some sort
of notification in the browser.

* src/main/java/org/glom/web/client/activity/DetailsActivity.java:
* src/main/java/org/glom/web/client/activity/ListActivity.java:
* src/main/java/org/glom/web/client/activity/TableSelectionActivity.java:
* src/main/java/org/glom/web/client/ui/details/RelatedListTable.java:
* src/main/java/org/glom/web/client/ui/list/ListViewTable.java: