Add Barnard catalog and various UI improvements to Catalog view

[mrosseel]

• Adding Barnard catalog, except for 2 objects which have an extra letter in their name which we can't handle! e.g. B 44a
• Allowing more description lines if there is no mag nor size info available (happens regularly in the Barnard catalog)
• Taking button hints into account when calculating nr of lines shown for the description

With button hints (2 lines of description):

Without button hints (3 lines of description)

Without button hints nor magnitude/size info nor common name line (5 lines of description)