Add checksum to of source to binary

[michael-dev]

The binary should report some info about the source code.

See http://www.atmel.com/webdoc/avrlibcreferencemanual/FAQ_1faq_binarydata.html for an approach.

https://balau82.wordpress.com/2012/02/19/linking-a-binary-blob-with-gcc/ https://stackoverflow.com/questions/4864866/c-c-with-gcc-statically-add-resource-files-to-executable-library