sunpy/sunpy — pull request #1092 by Cadair (2014-07-05 18:30:18+00:00)
Title: Allow the overriding of the databases value of defaultwaveunit in add_from_file.

The logic behind this is that sometimes you might be adding a file
with a odd waveunit that is not in the header, and you don't want
a global default but a file-by-file one.