Make the pthread cond wait in the getwork scheduler a timed wait in case we miss a wakeup.
Revert "Do away with usb resets entirely since we retry on both pipe and io errors now and they're of dubious value."

This reverts commit 4cde067658c9f34a6a98ad5385145432c44eb571.
Read pipe errors that don't clear are worth attempting to reset the usb.
Adjust antminer U1 timing according to command line frequency set, fixing the need for icarus timing on the command line.
Update NEWS.
Bump version to 3.12.2