Preview version of Seashore 0.5.0 released

[ctachme]

Given that it's been a super-long time since the last release I've
released a preview version of 0.5.0 at:

https://sourceforge.net/projects/seashore/files/

Also, I'm going to be phasing out these groups and ask that people use
the sourceforge forums:

https://sourceforge.net/projects/seashore/forums

Thank you!