Exception stuff

Start made on throwing nice exceptions that log possibly useful info
to the log file.
SPEAD stuff

Modified and added according to google spreadsheet from Ruby.

Need to check emission on certain events.
Need to allow data destination to be set.
Merge branch 'master' of github.com:ska-sa/corr

Conflicts:
	src/bf_functions.py

Moved spead initialisation logic to its own function which
conflicted.
debugging of new spead stuff
Small bug fix in qdr check

calling c.<blah> instead of self.<blah>
binary point handling for calibration values
automatic metadata issue, various bug fixes

metadata is now automatically issued when passband parameters change.

various bug fixes in spead related functions
small bug fix
Merge branch 'master' of https://github.com/ska-sa/corr
calibration value load optimisation

Time down to 27 seconds for all antennas for single beam (from 45)
small bug fixes (thanks Ruby)
Merge branch 'master' of https://github.com/ska-sa/corr
Optimised bf_write_int and write_int

write_int writes many transactions in parallel where possible.

bf_write_int sets up transmission of all frequencies to take advantage
of parallel transmission
Bug in non_blocking_request fixed

Sometimes data is in the reply arguments, as well as the informs.
Full reply and inform arguments now returned.
bug fixes for non_blocking_request

small fixes. currently timing out while waiting for responses
from certain FPGAs in non_blocking_request. Unclear why
Merge branch 'master' of https://github.com/ska-sa/corr
word info for cal values

number of bits and binary point now configuration settings
so that values not hard-coded
optimisations optional, cal data size in config

Converted last few self.config[... to self.get_param(...
Made write optimisations optional
Made calibration data sizes configuration parameter
Merge branch 'master' of github.com:ska-sa/corr

Conflicts:
	src/bf_functions.py
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