When e.g. test-leaks.lua fails, it will cause a Lua error before starting the
test runner. This means that the test will just hang, because nothing causes
awesome to quit.
Handle this by starting a timer when the test runner is loaded and quitting
awesome in there if no test run was started yet. This only works if all tests
load the runner before doing anything that could fail, so the require("_runner")
is moved to the beginning in every test.
Signed-off-by: Uli Schlachter <psychon@znc.in>