Positional information for binaries without orbit information

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.

The rationale for using the new elements is to maintain a clean separation between systems for which orbital elements are known and those for which they are not: semimajor axis and projected separation are in general two different quantities. The reason to maintain both angular and linear values of the separation is to keep the observational value that is not dependent on distance estimates available.