Release of FragIt 1.3

I'm proud to announce the immediate availability of FragIt 1.3!

From the release notes:

 * Stabilization of the API for 3rd party uses

 * API has support for a QM-region in the XYZ-MFCC
   writer. This QM-region can be expanded by including
   covalently bound or hydrogen bound neighbours.

   This support is slated to be included more generally
   in a future fragit 1.4 release series.

 * A visually more pleasing color scheme. We are no
   longer living in an 8-bit world.

 * FragIt now exits more cleanly if it cannot find itself.

The visually more pleasing color scheme was discussed in a previous post.