Improved how caching of filtered data is handled

Added the option to restrict database queries to a time range described by mimimum and maximum time stamps

Scaled all histogram rows to have a maximum of 1.

Added unit tests for DatasetContainer

Added unit tests for Plotter class

Removed hard dependency of DatasetContainer on Plotter and DatasetFilter classes

Reorganized imports

Renamed classes to adhere to PEP8

Documentation pass

Changed tests including datapoint to use datetime.datetime for a timestamp.

Added docstrings to test functions

Added Eclipse project files to .gitignore file

Removed Ecipse project files from repository

Improved some conditions in acceptance_tester, extended unit_tests accordingly

Added unit tests for dataset_filter