selenium-server-standalone 2.34

Closes #21776.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
grads: point to documentation in caveats
luarucks: unconditionally apply patch

Unconditionally apply patch to skip +w testing, and try to
document it better.
ispell: don't hard-code yacc path

Closes #21779.
Remove keg test dependency on formula
Remove hardcoded paths in keg tests
Add tests to demonstrate failure to prune empty directories
Keep track of pruned parent directories
Always prune empty toplevel directories when unlinking