[pypy-dev] lib-python and app-level (py.test -A) tests unified

FYI, I have unified the builders for lib-python and py.test -A tests for compiled pypy-c. These means that each night we compile less pypy-c and reuse them more. Builders with "app-level" in their name usually imply now running the lib-python tests too. Stackless tests still run only the py.test -A ones, pypy-c-jit tests the lib-python one plus the jit quality ones. Samuele