SM6FBQ / HackRF clone - History

Don't require a C++ compiler

By default, CMake assumes that the project is using both C and C++. By
explicitly passing 'C' as argument of the project() macro, we tell CMake
that only C is used, which prevents CMake from erroring out if a C++
compiler doesn't exist.

Merge pull request #468 from dominicgs/appveyor

Appveyor

Merge pull request #467 from dominicgs/windows_build_warnings

Remove Windows build warnings

DFU serial number - avoid reading serial from flash chip
Set a DFU mode specific serial number

Explicitly cast variables to silence Windows build warnings

Add helper functions for parsing frequency arguments

Calculate using doubles and cast to float at the last moment