syncing with sources
limnCbfTVT now computes scale=0 TVT, and that is now passed back to fctx->cornerCB corner tester
syncing with source
main change: now can use a callback function as part of determining which vertices count as a corner
syncing with source
fixing problem with nan generation from scale>0 vertex pos == orig pos
syncing with source
more complete use of nrrdHestNrrdNoTTY instead of nrrdHestNrrd