* Fixed context iterators for PoseChannels. The actual selection test was missing (but layer visibility was getting checked). Also added check for hidden bones here too. * Removed unnecessary defines added by mfoxdogg in BKE_context.h * Removed the old hacks in 'Clear ...' operators for ensuring that object animation (ipos/actions) don't overwrite poses. These are no longer necessary, since normal animation calculation is only done in a separate step on frame-changes now. * Removed the manual checks for layer visibility from 'Clear ...' operators, since that's taken care of by context iterators.