This adds idle hog tinting. Active hog tinting still needed.

let log know when a test finished properly, so that an unexpected termination (segfault, divbyzero, etc) is easier to tell apart from test fail

* fix divbyzero found by GetGravity test (cWindSpeed was used where cMaxWindSpeed should have been) * make GetGravity return same integer value that was given by SetGravity (by rounding away precision errors rather than just truncate) - a problem also identified by the test :P

test for GetGravity and SetGravity