Add option to disable timed dependant tests

[kanavin]

The disabled tests rely on timing to pass correctly. On a virtualized system under heavy load, these tests randomly fail because they miss a timer or other timing related issues.

[notroj]

Thanks for the PR. This looks like a good idea but I think it should be done with a plain AC_DEFINE(HAVE_xxx) rather than putting something in apr.h which becomes part of the API.

[kanavin]

Thanks for the PR. This looks like a good idea but I think it should be done with a plain AC_DEFINE(HAVE_xxx) rather than putting something in apr.h which becomes part of the API.

This has been corrected now.