Merge branch 'next'

* next:
  chore, refactor mod flags for gand_get_series() into make var MOD_LDFLAGS
  hygiene, use matlab_CFLAGS instead of reinventing the wheel in cli/matlab's Makefile
  chore, turn Werror off before doing matlab check
  chore, check for mex.h upon SXE_CHECK_MATLAB
  chore, check for splicing features via SXE_CHECK_*_SPLICE