Added separate test beds for pyNCS_unittest and pyST_unittest
loopback communicator interface for testing
addrgroupbase for addrgroups that are not tied to a setup/chip.
For the moment only used in tests, but in can be useful in the future.
returned function instead of result of get_slice
Implemented issue #11
rejuvenated pyNCS_unittest
Spikelists can now i=be instantiated with spikelist objects