Add ability to refer to tiddlers by a list of aliases

[JeremyRuston]

Add the ability to associate a list of aliases to each tiddler that can be used to refer to it interchangeably with the ordinary title of the tiddler.

This feature can also be used to provide translation of shadow tiddler titles. For instance if in Franglais, "MainMenu?" translates as "MenuDeMain?" then, the tiddler should be created with the title "MenuDeMain?", and "MainMenu?" as an alias.

[UdoBorkowski]

Also ensure that links through an alias of tiddler T are listed in the "References" of T.

[UdoBorkowski]

Provided a patch to implement this feature.

[cdent]

The alias idea is complicated enough that several different implementation ideas have been discussed since this ticket.