Add tutorial for adding more completion types and added new completion

Add tutorial for adding more completion types and added new completion
types:

2009-04-24  Miguel de Icaza  <miguel@novell.com>

	* complete.cs (CompletionElementInitializer): New completion class
	to support completing inside a C# 3 element initializer, so this
	allows completion for Silverlight situations where it is very
	common to do:

	new TextBlock () { Fo<TAB>

	(CompletionSimpleName): Expose the prefix that was
	passed to the simple name.

	* cs-parser.jay (object_or_collection_initializer): Add support
	for element_initializers.

	* expression.cs (CollectionOrObjectInitializers.DoResolve):
	special case completion expressions as this method aggressively
	collects data before it operates, and errors were being thrown
	earlier than we were able to complete.

svn path=/trunk/mcs/; revision=132592