darwin: fix reset device

darwin: fix reset device

This commit fixes the backend of reset device to restore the state
of the device if possible. This fixes a bug introduced in
c14ab5fc4d22749aab9e3534d56012718a0b0f67. The previous commit
was necessary due to changes in the system USB stack that
essentially turned the ResetDevice function into a no-op. This
required libusb to move to USBDevuceReEnumerate to effectively
reset the device. The problem is that both the device handle and
libusb devices became invalid. This commit fixes the bug by
waiting for the re-enumeration to complete then 1) checking
whether the descriptors changed, 2) restoring the active
configuration, and 3) restoring claimed interfaces.

Closes #523

Signed-off-by: Nathan Hjelm <hjelmn@me.com>