[bp/r45836] Since the Jison Parser is only for programmers for now, removing from the admin panel. The problem is that end users tend to click everything to try stuff, but then, they report bugs and don't know they are Jison Parser bugs

[bp/r45822] [FIX] jison parser: Disable feature_jison_wiki_parser in the systemConfiguration, which switches it off and disables the prefs needed to turn it back on.
This is to reduce support issues resulting from people trying it out by mistake and running into trouble.
Can be overridden by just commenting the line out, or adding it to a tiki.ini file, for development (thanks marclaporte)