Reports Exceptions

[ffgalindo]

Need to figure out and add or rethink how connection exceptions are handled when 'reports' sub-command is used instead of 'stats'.

[ffgalindo]

Removed the old "DSS" prefix from the exception Class names, which stood for DynafedStorageStats.
Removed importing "from dynafed_storagestats import exceptions" to "import dyanfed_storagestats.exceptions" so the prefix is not necessary.
Updated all raises and calls to exceptions.
Dev branch.