Wed Mar 12 17:01:07 2014  Jiri (George) Lebl <jirka@5z.com>

	* src/funclib.c, src/calc.h: Implement NonzeroColumns and
	  NonzeroElements to return indices of nonzero columns in a matrix
	  and elements in a vector

	* src/matrixw.[ch]: the _vindex function could have returned NULL,
	  though it didn't seem to cause any crashes

	* src/geniustests.txt: test the above
fixup changelog entry