Updated travis.yml to allow build_sphinx command
Commented out much of the travis build temporarily for testing
added code to allow returning the warnings count from build_sphinx
add "-w" to build_sphinx call in travis
Reordered warnings-returncode option to make it less prominent
Updated travis.yml to use correct shell scripts and do the sphinx pre-install
fixed travis.yml to properly match build_sphinx even if it has options
changed failure retcode to just be 1
adjust .travis.yml to remove commented-out portion
Show warning for floating-point/integer conversion except if the quantity is truly dimensionless (i.e. unit == u.dimensionless, but not e.g. u.m / u.km).
Add configuration item, and avoid unnecessary import
Renamed configuration item
Added docs about float/int/numpy conversion
Compare units directly to pre-computed dimensionless object.
Use a better test for dimensionless of units in numeric conversions
Fix config item description
Fix function syntax so they are recognized by intersphinx
added graphviz and latex
switched to texlive-latex-extra
added dvipng to apt-get for sphinx build