1.7.21

-- Incorrectly removed chkFlag from hmrG_BlockAvg* user functions. chkFlag is a parameter that if true requires, for each channel, ALL corresponding subjects channels to pass before averaging that channel. TBD: Currently we set it to false unconditionally. In the future chkFlag should be a user-settable input parameter.

-- Fixed some hidden problems with comparing homer2 and homer3 results in unit tests.