Rename GlomDocument to DocumentInfo and update associated methods.

Rename GlomDocument to DocumentInfo and update associated methods.

This is a rename-only refactor. No functionality has been added or
removed.

* src/main/java/org/glom/web/client/OnlineGlomService.java:
* src/main/java/org/glom/web/client/OnlineGlomServiceAsync.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/server/ConfiguredDocument.java:
* src/main/java/org/glom/web/server/OnlineGlomServiceImpl.java:
* src/main/java/org/glom/web/shared/DocumentInfo.java: