pre fpga split commit

Committing now to try to clean up separation of fpga stuff
from corr2. corr2 not in a state to be used
Merge branch 'master' of https://github.com/ska-sa/corr2

Conflicts:
	src/__init__.py
	src/fxcorrelator.py
	src/misc.py
	src/mock_rts.py
	src/xengine_fpga.py
Moved to casperfpga
casperfpga extraction, bug fixes

Changes related to separation of agnostic FPGA stuff from corr2.

Various bug fixes so that basic instrument can be brought up and
simple initialisation done