Update simulator networks to have proper quantization
Add pi constant

Also some changes to properly log to console when no slaves are found

A few improvements from the Vitsch Electronics CVS
Use log_send() for all logging and add context (DEBUG/WARNING/ERROR) info.
A little bit more comments

The controller_load functions will set it to the .ctrl filename.
Modifiy dumpdot to use it to make subgraphs. This way we get a nice
grouping of blocks per file.

Also fix some reentrancy issues in the controller_load functions.