report descriptor parser

Hi Tony,

thanks so much for your work on retrieving the report descriptor from the device.
In the past few days I have been working on a parser to parse the report descriptor, so that the data from the reports can be more easily read for further use of the data.

I thought this might be of interest for your work as well.

I have also merged in the changes from signal11's repository, as there were some fixes in there for some backends.

And I started on a CMake build system as an alternative to the autotools one.

sincerely,
Marije