Another checksum test that should be skipped on Windows due to slight differences in floating point rounding.  I did double check that the floating point values are slight different on Windows than I get on Linux, thus making the checksums different.
Fix get_graphviz_version()'s regexp searching for a version number.  Because this used '*', any string matched the expression.  On my version of graphviz, 'dot -V' returned 'dot - graphviz version 2.30.1 (20130214.1330)', so get_graphviz_version() returned 'dot' as the version.
Merge branch 'v0.3.x' of github.com:astropy/astropy into v0.3.x