FreeBSD/build: Files specific for building on FreeBSD

FreeBSD/build: Files specific for building on FreeBSD

 - README.FreeBSD for the description of the current work thusfar
 - do_freebsd.sh, the srcipt to run autobuild/compile/tests
 - autogen_freebsd.sh set the options to use in the auto/configure tools
 - do_freebsd.sh: Install bash and softlink, so other bash scripts can
   run as is. Using /usr/bin/env would be more compliant.
   But not for now. This makes it compatible with the std-linux environment
 - So now we can even have Clang in /usr/bin and /usr/local/bin
   and still get the right one.
 - Use less error suppression, but start fixing warning.

Signed-off-by: Willem Jan Withagen <wjw@digiware.nl>