Bndtools Release Candidate 1 for 5.1.0

The 5.1.0.RC1 build is now available as of May 15 2020. This is a big release with lots of new features and performance enhancements. Some highlights:

Please try it out and provide feedback so we can iron out the last bits.

Release notes are at https://github.com/bndtools/bnd/wiki/Changes-in-5.1.0

Please try this out and report any issues.