User:Brion VIBBER/Math fixes


 * BUGGY 86962 - 6722 & 18912 - function spacing in HTML, spanish \sen, \operatorname spacing in LaTeX
 * 87117 - followup?
 * 86965 - 26380 - \widetilde -- tests & merged
 * 87092 - 19547 - add ' and ` chars in \text{...} -- is this really sufficient? maybe not but it's ok for now
 * 87284 - 27324 - add \euro & friends, tweak HTML output of some others -- tests & merged!
 * 87298 - 27754 - greek chars -- tests & merged!
 * MathML going away 87934 - mathml tweak
 * 88030 - mathml followup
 * 88260 - mathml minus
 * 87936 - \sin without params failing
 * 87941 - function spacing