Make version comparison readable

This also fixes an endian issue with the comparison of the last two
bytes.  According to the logging output, these bytes are in little
endian order so the last byte is more significant in the comparison.
Rename `'s/supported_device/known_device/g'`

An `ambit_supported_device_t` with a `supported` value of `false` is
confusing at best.
Export clock's support status in `ambit_device_info_t`

This allows for dropping the `ambit_known_device_t` pointer from
`ambit_object_t`.
Fix log message
Check valid temperature range
Fixes #31
Added initial support for Ambit 2 R
Merge remote-tracking branch 'allfather/master' into Qt5_Client
Having correct builds with either Qt5 or Qt4

For now if Qt5 is present it will be the preffered version
Adding some CMake specific files and folders to the ignore file