* rework who.c so it doesn't use svput() and friends but rather preregistered callbac...

* rework who.c so it doesn't use svput() and friends but rather preregistered callback hooks (like the other new stuff)
* more syntax error detections and warnings in the template engine...
* change trailing_js to be a static template hook too
* pre-evaluate conditionals too
* swap startup sequence so pre-evaluation actualy works (first register hooks, then parse templates)
* global function to be used by string tmplput hooks which evaluates escaping demanded by template tokens in a central place
* fix spelling in some mobile templates
* move SERV: template hooks into serv_func.c