Support query result blocks with the wave unit kev.

This fixes #766.
Merge branch 'master' of https://github.com/sunpy/sunpy into issue766
Merge branch 'master' of https://github.com/sunpy/sunpy into issue766
Merge pull request #767 from derdon/issue766

Support query result blocks with the wave unit kev.
Merge branch 'master' of https://github.com/sunpy/sunpy into dbtest-travis