Add the capability API
Add hotplug support
Layout
Untabify Timeval
Added more libusb-1.0.16 support

- Extended Verbosity with the PrintDebug constructor.

- Added the System.USB.Misc module which exports
  the hasCapability & libusbVersion functions.

- Added the deviceSpeed, portNumber, portNumbers and parent functions to
  System.USB.Enumeration.

- Added the setAutoDetachKernelDriver to System.USB.DeviceHandling.

- The hotplug callback should now return a CallbackRegistrationStatus
  instead of a Bool.
Added the function toVersion :: LibusbVersion -> Version

Also improved documentation.
Make sure the parent device isn't freed
Reformatted the Changelog file