Extension:ThumbParser

Adds ParserFunktion #thumb that prints the thumb size that a user has defined It takes three different parameters


 * the thumbsize
 * the thumbsize with px added at the end
 * the thumbsize +10 with px added (size of a thumb with box)
 * the thumbsize with px added at the end
 * the thumbsize +10 with px added (size of a thumb with box)
 * the thumbsize +10 with px added (size of a thumb with box)