Added binary separation/position angle information from Raghavan et al. (2006).
Projected separations in AU are recalculated using the distance values included in the file.

Three new elements are used to represent these systems:
separation = separation between the components, in arcseconds
positionangle = position angle of the secondary, in degrees
projected = projected separation between the components, in AU

The cleanup.py script is updated to handle the new elements.
Use unit attribute to distinguish angular and linear projected separation values, using the
<separation> tag for both. Updated cleanup.py accordingly.
Merge pull request #294 from mistertribs/orbitless

 Positional information for binaries without orbit information