improved function to estimate median. Some testing is still required to make sure all exceptions are handled properly

solved issue with zeros scattered in median array. More extensive testing needed to confirm no weird exceptions are found where the code still does not work

Main code for implementation of median in yori-grid. Still untested and requiring further development

initial changes for 1.7.0. batch_size is now an option and requirements.txt has been added to allow choosing module versions

Aerosol requests implemented