vera++ 1.2.1

Closes #20356.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
git: add note about 1.8.3 being broken
Sniff for non-tarred gzips

Don't try to untar non-tarred gzips.
tesseract: use normal download strategy
graphviz: update --devel version
Ghostscript: add DjVU support

Closes #16830.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
cmake: simplify test slightly