new data model (and documentation)

[moustakas]

This PR addresses #188 by

• Moving the METADATA HDU first;
• Adding a new SPECPHOT HDU containing the spectrophotometric fitting results and ensuring that a maximum number of columns are in common between running fastspec (joint spectroscopic + photometric fitting) and fastphot (photometric fitting only);
• Reorganizing and simplifying the FASTSPEC HDU (only present for fastspec) to only contain spectroscopic fitting results.
• In addition, in fastspec mode there is also the optional MODELS HDU containing the camera-merged spectroscopic models.

See this spreadsheet for additional details:
https://docs.google.com/spreadsheets/d/1DnCPhu-62b8JgC7ZjY422sh9I006lJ4a1gt8Inwij_M/edit?gid=0#gid=0

There are also some bug fixes and I've added the 2MASS J-band as an output (rest-frame) bandpass.

[coveralls]

Pull Request Test Coverage Report for Build 12184070831

Details

• 284 of 462 (61.47%) changed or added relevant lines in 7 files are covered.
• 4 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+9.7%) to 50.317%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
py/fastspecfit/linetable.py	1	2	50.0%
py/fastspecfit/photometry.py	2	3	66.67%
py/fastspecfit/emlines.py	61	80	76.25%
py/fastspecfit/io.py	149	193	77.2%
py/fastspecfit/qa.py	2	115	1.74%

Files with Coverage Reduction	New Missed Lines	%
py/fastspecfit/qa.py	2	1.07%
py/fastspecfit/io.py	2	53.75%

Totals
Change from base Build 12166179538:	9.7%
Covered Lines:	3178
Relevant Lines:	6316

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💛 - Coveralls