simplified regexp

Ok, I think I've got it now. The following matches all...

1. starting with a literal `$:`
2. then any number of character not a whitespace, `<` or  `|`
3. closing with anything that is, again, not a whitespace, `<` or  `|`

Test here...

http://tbdemo.tiddlyspot.com/#Autolink%20System%20Tiddlers

core/modules/parsers/wikiparser/rules/syslink.js

@@ -18,7 +18,7 @@ exports.types = {inline: true};
 exports.init = function(parser) {
 	this.parser = parser;
 	// Regexp to match
-	this.matchRegExp = /~?(?:\$):[^\s<>{}\[\]`|'"\\^~]+(?:\/|\b)/mg;
+	this.matchRegExp = /~?\$:[^\s<|]+(?:[^\s<|])/mg;
 };
 
 exports.parse = function() {