PLCobject: Call "stop" and "cleanup" methods from python runtime files in reverse order compared to "init" and "start".

Non significant changes to mute GCC warnings about unused variables.

Fixed sequel of earlier commit in PLCGenerator.py. Some ref to temporary variables are still not using the _TMP_ prefix. They are quite hard to find, so to be continued...

variable access code moved from plc_debug.c to targets/var_access.c for easiewr re-use in ext.

Swap CTN code gen and Libraries code generation order. In general library part of an extension needs to be computed before CTN part.

yslt_noindent : Avoid YSLT's indent logic to interfere when using linequote.