Essential change to mb_ucfirst to allow for filenames such as File:Żółty bratek.jpg. I'm not entirely sure why forcing utf-8 broke the routine before, but this now seems to work. While we are at it, prettify the error output by using the same function.
Add multibyte UTF-8 encoding, make a few output messages nicer, allow url escape characters in gallery lists (as seen e.g. in <Spermophilus> which has Image:Richardson%27s-Szmurlo.jpg).
Correct previous commit - use "rawurldecode" rather than plain urldecode, to preserve plus signs in gallery file lists (e.g. https://commons.wikimedia.org/wiki/Tecoma_stans, which includede "File:Tecoma stans, flowers+pods.jpg".
Merge pull request #69 from hyanwong/wikimedia_improvements_utf_correction

Simplest bugfix for new multiple taxonomy code - based on latest branch