Amendment to r36250.

Amendment to r36250.
Rather than adding a few extra characters to a single locale just to make it work. We should extend our base linkTrail to work properly in a universal matter.
From: http://www.regular-expressions.info/posixbrackets.html#class
The Unicode format for mathing all [:alpha:] characters is \p{L&}
I tested this on my own machine. Before applying it 99% of the special characters inside of Wikipedia's EditTools box would not be considered part of a linktrail.
However, after changing the a-z to use \p{L&} every last character listed there was considered part of the LinkTrail and that includes the ones that r36250 tried to fix.
Additionally, I also added ' to allow matching, but only at the start of the linktrail to allow for things like [[Bar]]'s to link correctly. It was tested and does not break the ''s used for emphasis, and does not linkify single quotes used to quote things rather than as an apostraphe.
I may make a second commit later to remove legacy $linkTrail definitions which are no longer needed.