Renamed struct cc_results to struct cc_test.

Added cc_test_t typedef for "struct cc_test *".  Changed name of test
function parameter from _cc_results_ to cc_test.  This makes the test
function signature simple: "void my_test(cc_test_t cc_test)".

Changed name of cc_def "test_function" field to "func" to match the CC_TEST()
macro.

Changed "test" field of cc_case struct to "def" to be less confusing where
there are references to cc_test structs.
Changed name of test function parameter from "cc_test" to "cctest".