next task

[eeholmes]

• add the cols and sortcols arguments cols = {'selectcols': [], 'sortcols': []}
• add method to return colnames for the full tables. Add as method for TablesResponse and DatasetsResponse. Then add getcols().
• Add the ESU/DPS names
• Find way to get all the column values
• Add documentation for caxutils
• Add documentation for the classes DatasetsResponse and TablesResponse
• Add a favicon, make a hex sticker
• make documentation look more like http://icesat2sliderule.org/rtd/
• change the version to look more normal; I think this will be ok when I make a release??