To work with Tacx Fortius on 32/64 bit platforms without
having to install the Tacx software (which requires the
user to pay to upgrade to TTS2/3/4).
Fixes#550.
This update completes support for USB2 sticks for ANT+ devices
in train view. The code now works on Linux and Mac as well as
Windows.
IOKit is now a required framework for builds on Mac OSX and
src.pro has been updated accordingly.
I have also added a tarball of the required version of libusb
in a new 'contrib' directory. Users may wish to use a later
version or download from an alternative source, but this
version is guaranteed to work.
Fixes#310
