Bug 125600 [Field Assist] - popup shell should be resizable with size retained
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalAdapter.java
*            the keystroke that will invoke the content proposal popup. If
	 *            this value is <code>null</code>, then proposals will be
	 *            activated automatically when any of the auto activation
	 *            characters are typed.
	 * @param autoActivationCharacters
	 *            An array of characters that trigger auto-activation of content
	 *            proposal. If specified, these characters will trigger
	 *            auto-activation of the proposal popup, regardless of whether
	 *            an explicit invocation keyStroke was specified. If this
	 *            parameter is <code>null</code>, then only a specified
	 *            keyStroke will invoke content proposal. If this parameter is
	 *            <code>null</code> and the keyStroke parameter is
	 *            <code>null</code>, then all alphanumeric characters will
	 *            auto-activate content proposal.
	 * @param propagateKeys
	 *            a boolean that indicates whether key events (including
	 *            auto-activation characters) should be propagated to the
	 *            adapted control when the proposal popup is open.
	 * @param filterStyle
	 *            a constant indicating whether keystrokes in the proposal popup
	 *            should filter the proposals shown <code>FILTER_NONE</code>,
	 *            <code>FILTER_CUMULATIVE</code>, or
	 *            <code>FILTER_CHARACTER</code>
	 * @param acceptance
	 *            a constant indicating how an accepted proposal should affect
	 *            the control's content. Should be one of
	 *            <code>PROPOSAL_INSERT</code>, <code>PROPOSAL_REPLACE</code>,
	 *            or <code>PROPOSAL_IGNORE</code>
	 * 
	 */