Add options for TSan and UBSan
Avoid CMP0054 warning

Annoying, but it's a nice thing to have, so I guess this is an
acceptable loss of a quoted variable.
Integrate sanitizer options with CTest

Generate the dashboard script with the same options as the build for
sanitizers and such.

The inclusion of CTest must happen after the support scripts because
they now set variables which are used in the DartConfiguration.tcl file.
Use the new CTest configuration file
Remove clang-specific variable

If GCC ever supports it, don't assume it needs to masquerade as clang
for it.
Lock down the build types allowed