Add some checks.

Add some checks.

	* src/main/java/org/glom/web/client/activity/DetailsActivity.java:
	RelatedListNavigationButtonCell.onEnterKeyDown(), setData():
	* src/main/java/org/glom/web/client/ui/details/RelatedListTable.java:
	getDataProvider():
	* src/main/java/org/glom/web/client/ui/list/ListTable.java:
	addColumn():
	* src/main/java/org/glom/web/server/database/DBAccess.java:
	convertResultSetToDTO(), getPortal():
	* src/main/java/org/glom/web/server/database/ListDBAccess.java
	getListData():
	* src/main/java/org/glom/web/server/database/RelatedListDBAccess.java:
	Add checks for null objects and out of range access, with log messages to
	give hints so we can fix these properly.