Fix bug which lead to infinite loop when parsing strings containing $0 (e.g. http://commons.wikimedia.org/wiki/File:Yangzhou_-_supermarket_-_watermelons_-_P1070029.JPG which has

description = "{{en|Watermelons of 3 varieties sold in a Yangzhou supermarket. This is January, so they must have been brought from somewhere like Hainan, and are fairly expensive (4Y, i.e. $0.70, per pound).}}" )

By using str_replace whenever a constant string is being replaced, rather than preg_replace, we avoid using regexp substitution in the replacement string, and the code is also simpler and faster.
Allow strip_tags to strip nested tags such as <b><i>foo</i></b> or even (as occurs in parsed wikitext) <b><i>foo</b></i>. Also strip <br> and <br /> tags (which do not have closing tags).
Change incorrectly marked "static" variables to "private". These are class variables that should contain unique values for each separate instantiated object.

Presumably this is simply a typo and they were meant to be marked "private" originally
The current UTF checking code causes a segfault on some strings. See http://stackoverflow.com/questions/1282986/utf-8-validation-in-php-without-using-preg-match. Replace it with the builtin version.
Merge pull request #66 from eliagbayani/master

DATA-1342 ADU Virtual Museaum, follow-up work on Turbellarian, Rotifers.
Merge pull request #64 from hyanwong/wikiparser_preg_bugfix

Wikiparser preg bugfix
Merge pull request #65 from hyanwong/wikimedia_minor_improvements

Wikimedia minor improvements