Detect vendor prefixes more sanely.

Previously it would pick the prefixed version for Chrome, even when the unprefixed was available. Also use the transform and not the transition property for testing, since safari still doesn't support unprefixed transform but does support unprefixed transition.
We explicitly did `return false` to break out of `$.each` loop. The same won't work with native `forEach`. So, if you want to stick for native, you have to account for the fact iteration will continue after the appropriate prefix is already found.