Create .rst documentation from the vmod.vcc file.

This causes a change of syntax for the vcc file, it is however
very slight:  "Module", "Init", "Function", "Object" and "Method" needs
a "$" prefix, and the methods refer to the previous $Objecet without
the enclosing { }.

The first contiguous set of lines starting with "#" is treated as
a copyright notice, and emitted last, unless the first line is "#-"