Merge pull request #1372 from hamogu/fixlatex

    fix bug in writing AASTex tables
    Conflicts:

        astropy/io/ascii/tests/test_write.py
Add missing reference that should have been added back in c230ef53cecea9b16d4124ad8804ac1609e24959 which merged a change that references this document.
Merge pull request #1405 from mdboom/unit/coverage

Improve astropy.units test coverage
Conflicts:

	astropy/units/core.py
	astropy/units/format/utils.py
	astropy/units/tests/test_equivalencies.py
	astropy/units/tests/test_quantity.py