* Bug: In CRL/technos.node180.gf180mcu_c4m.iolib.py, remove the VDD and
VSS ring terminals in the pad as only *some* of the have it.
Assume that it is a bug from GF. The power rail will still be ok
as it connect by abutment (with the filler & other I/O pads).
* New: In cumulus.plugins.block.configuration.py, added support for
iterable I/O pad specifications in ioPads argument.
* New: In cumulus.plugins.core2chip.core2chip.py, add support for
any number of control signals on I/O pads. Not fully implemented
yet, as we only allow to hard-wire them either to one or zero.
Raise an error if _connect() fails to find a master net, so
we don't fail strangely later...