Add in utility function to combine datamaps

[bmritz]

Thin wrapper perhaps around a dict concatenation.
Check for address conflicts and raise errors if they exist.

[bmritz]

consider: https://docs.python.org/3/library/collections.html#chainmap-objects

[bmritz]

def dict_concat(*args):
first = copy.copy(args[0])
assert isinstance(first, dict)
try:
rest = args[1:]
except IndexError:
return first
for d in rest:
assert isinstance(d, dict)
assert len(set(d).intersection(first)) == 0
first.update(d)
return first