Added interval to git_slice to differentiate between seconds and minutes.  Minutes were getting an extra minute in the file

Cleaned up the metadata to meet expectations from IAGA2002,  ie latitiude/longitude are now strings, etc.

Added basic checking of start/end times. Divide by 1000 to pass back actual data.  Post process data, to convert traces from Masked arrays, to ndarrays with nans for gaps, and fill stretch the beginning and ending of arrays with nans, to make the arrays the same length, as the time asked for.

Added channel handling to base class, since the Controller uses the algorithm to confirm classes into and out of the Algorithm

put metadata in sub-dictionary, added data_interval_type in outer dictionary,  added code to deal with the new observatory dictionary format