Bug 53742 [templates] add different ui for linked mode depending on usage
Linked mode should allow to be configured programmatically to have a different ui. This would allow the instance that is setting up linked mode to determine how it will look like. Use case is auto-closing: the box is too disturbing there, while it may be good for more complex templates.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/JavaCompletionProposal.java
* @see ICompletionProposalExtension#apply(IDocument, char, int)
	 */
	public void apply(IDocument document, char trigger, int offset) {
		try {
			
			int delta= offset - (fReplacementOffset + fReplacementLength);
			if (delta > 0)
				fReplacementLength += delta;
			
			String string;
			if (trigger == (char) 0) {
				string= fReplacementString;
			} else {
				StringBuffer buffer= new StringBuffer(fReplacementString);
				
				if ((fCursorPosition > 0 && fCursorPosition <= buffer.length() && buffer.charAt(fCursorPosition - 1) != trigger)) {
					buffer.insert(fCursorPosition, trigger);
					++fCursorPosition;
				}
				
				string= buffer.toString();
			}
			
			int referenceOffset= fReplacementOffset + fReplacementLength;
			final ReferenceTracker referenceTracker= new ReferenceTracker();
			referenceTracker.preReplace(document, referenceOffset);
			replace(document, fReplacementOffset, fReplacementLength, string);
			referenceOffset= referenceTracker.postReplace(document);			
			fReplacementOffset= referenceOffset - (string == null ? 0 : string.length());
			if (fTextViewer != null && string != null) {