More fixes after changing self-test scheme for OpenCl. Some of these fixes
only work around self-test inconsistencies but some were real bugs.
Speed up self-tests for CUDA too.
Add -DJTR_RELEASE_BUILD which can change some defaults for releases.
Currently it's only used to disable the hacky backtick-auto-conf stuff
in Makefile.
Add self tests that ensure min/max keys per crypt are sane.