Merge pull request #715 from astrofrog/docs/mention-xcode-installation

Clarification to install docs regarding compilers
Merge pull request #736 from nhmc/cosmology_doc_typo

fix typo
Merge pull request #722 from astrofrog/io/more-hdf5-fixes

Minor HDF5 fixes, and added Python 3.2 optional dependency testing to Travis
Conflicts:

	.travis.yml
Merge pull request #701 from mdboom/unit/dimensionless_repr

Dimensionless unit looks the same regardless of scale
Merge pull request #737 from kbarbary/fix-theme-css-import

Remove explicit inclusion of theme css file
Merge pull request #730 from eteq/docs/note-clxcode-option

Tweaked discussion of installing XCode command line tools
Merge pull request #738 from mdboom/vo/doc-fixes

Minor docstring fix for io.votable
Merge pull request #740 from zblz/boltzmann

correct units of cgs.k_B to erg/K
Merge pull request #742 from astrofrog/setup/fix-missing-files-sdist

configobj_py3 not included in v0.2b2