fix, PEBKAC, use MEX_LDFLAGS
chore, PEBKAC, define EXTRA_DIST before += assigning stuff to it
chore, only visit matlab/ subdir in cli in case we want the mex client
Merge branch 'core/matapi'

* core/matapi:
  chore, only visit matlab/ subdir in cli in case we want the mex client
  chore, PEBKAC, define EXTRA_DIST before += assigning stuff to it
  fix, PEBKAC, use MEX_LDFLAGS