Bug 125012 [Field Assist] Clarify lifecycle of the ILabelProvider used by ContentProposalAdapter
I20060119-0800 Clients who want to port their field content assistants from jface.text.contentassist to jface.fieldassist would expect to be able to supply an image in IContentProposal, e.g. with a 'Image getImage();' method as in ICompletionProposal. Without icons, e.g. proposals for java type names would look quite different from the ones you get in the java editor. There's also a lot more functionality in ICompletionProposal and the 4 ICompletionProposalExtension* interfaces. Some of those concepts must also be supported in fieldassist if clients such as the Find/Replace dialog and Java type completions in dialogs should switch (e.g. the additionalProposalInfo to show documentation for regex proposals, etc.). I can file separate bugs for these functionalities if you want to discuss them one by one.
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalAdapter.java
* 
		 * @return the return code
		 * 
		 * @see org.eclipse.jface.window.Window#open()
		 */
		public int open() {
			addControlListener();
			int value = super.open();
			showProposalDescription(getSelectedProposal().getDescription());
			return value;
		}
		/**
		 * Closes this popup. This method is extended to remove the control
		 * listener.
		 * 
		 * @return <code>true</code> if the window is (or was already) closed,
		 *         and <code>false</code> if it is still open
		 */
		public boolean close() {
			removeControlListener();
			return super.close();
		}
		/*
		 * Get the proposals from the proposal provider. The provider may or may
		 * not filter the proposals based on the specified filter text.
		 */
		private IContentProposal[] getProposals(String filterString) {
			if (proposalProvider == null)
				return null;
			int position = getControlContentAdapter().getCursorPosition(