Strip Unicode 6.3.0 directional formatting characters from title

Strip Unicode 6.3.0 directional formatting characters from title

Unicode 6.3.0 (September 2013) the added additional directional
formatting characters:

U+061C ARABIC LETTER MARK
U+2066 LEFT-TO-RIGHT ISOLATE
U+2067 RIGHT-TO-LEFT ISOLATE
U+2068 FIRST STRONG ISOLATE
U+2069 POP DIRECTIONAL ISOLATE

https://www.fileformat.info/info/unicode/version/6.3/index.htm

This change strips the new directional formatting characters from the
title like the directional formatting characters from Unicode 1.1.0
(June 1993).

Any existing titles containing the new Unicode directional formatting
characters get stripped by a run of maintenance/cleanupTitles.php after
deployment.

This change also allows to insert the new Unicode directional
formatting characters into the DISPLAYTITLE.

Change-Id: I2279f51048f5252c2e4280ec6a13f060ff9967cb