add Coefficients[AlgoFit/AlgoFitNL] + code tidying

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34080 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
4.9.265.0

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34081 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
#3392 headers


git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34082 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e