Temporarily reduced the decimal point accuracy of traintests

The decimal points accuracy of traintests is temporarily reduced
from 7 to 6, to ensure tests pass after some norm_total summation
accumulators were upgraded from 32-bit to 64-bit. This should be
reverted before v1.0 and the test data be replaced.
Readded CFIter alias MaskedCFIter for user compatability

Should be removed before release v1.0