ctest: only create buildid when submitting from Testing/ dir
In !2380 (merged) we taught CTest to pass extra information to CDash at submit time. This extra info is used by CDash to initialize a buildid.
ctest_submit(FILES)
can be used to send specific files to CDash.
These files are not necessarily associated with the build currently
being performed. For this reason, we modify the behavior of ctest_submit()
to only specify this extra info when we are submitting files from the
current build's Testing directory.
Edited by Brad King