-f/--failfast command line option for unittest. Issue 8074. Documentation still needed. Plus minor change to test_unittest to allow it to be run with python -m test.unittest

Note this removes the "non-keyword" or "keyword" phrases from these messages.

variable anymore.  It also forwards the LDFLAGS settings to the linker
when building a shared library.

But when the "dl" module is available, it gives a py3k deprecation warning.

Remove the "built-in objects" file.  It only contained two paragraphs of which only one contained useful information, which belongs in the ref manual however.