template: don't automatically include tmpl.h anymore

template: add quoting support inside {{ ... }} blocks

fix parsing of {! !} block after content the '{' and '!' characters were pushed back in the wrong order and so read as "!{" instead of "{!". add regress for this case, and for similar usage (02 change.)

template: fix possible use-after-free and drop the `render' sugar if some of the tp_* function fails, the inner code could free the template too (that's what galileo does), so `tp->tp_ret' would access free'd memory! Instead, add a local variable `tp_ret' to keep track of the return code. While here, drop the `render' shortand that adds the argument call, the template_reset function and adapt the regress.

import the template compiler i've been working on