Refactor the JSOC client into three steps:

* Query, return a list of records
* Stage data using request_data
* Download data using get_request

The last two are now contained in get() which makes the API much more like that
of the other clients such as VSO.

Also, massive doumentation improvements and include Time in the jsoc.attrs.
More documentation improvements.
Further improvements and units in Wave
Merge pull request #5 from Cadair/jsoc_improvements

JSOC  client query,get method changed