Feature/python reduce printing compiling

Recent changes lead to a printing of "Compiling xyz...." every time a JIT python module is loaded - even if it's not actually compiled. It's not possible to identify if sth. actually has to be compiled, e.g. because headers could have changed.

I added a handler to print this info only if the compile command takes more than one second, therefore loading a module should not be considered any more as compiling.