Fix bug #5409 ("The header for dosage-based output is not equal to that of prob-based ProbABEL output").

Adjusted the checks accordingly.
- Currently the test_mms.sh is broken (probably because the mmscore function is under construction by Maarten K.), so that one is not tested (however, given that I made the same changes as in the other test*.sh files, I don't expect trouble).
- The run_diff.sh script is now simpler because we don't need to pass arguments to diff anymore.
- Note that previously, for the additive model the header of the chi^2 column was "chi2_SNP", whereas for the other models it was e.g. "chi2_SNP_dom". For consistency I've change the column name to "chi2_SNP_add"




git-svn-id: svn://svn.r-forge.r-project.org/svnroot/genabel@1655 edb9625f-4e0d-4859-8d74-9fd3b1da38cb