[FIX] create data_home folder if it does not exist
[FIX] fixed error handling in AsymmetricGaussIntegrator

     loooks like scipy.optimize.leastsq changed conversion
     check, so that given examples does not converge anymore
[FIX] startup.py now runs all startup files again
[FIX] fixed broken startup for creating emzed_files folder
[FEATURE] extended downloader.py