Second Prerelease

This adds a few new features since v0.1-alpha. In particular:

• new "bug tag" command lets you tag categories to bugs
• "bug list tagname" will now list all bugs tagged with "tagname"
• "bug create -n" option will create a bug with an empty Description, instead of opening an editor. This can be used for scripting batch creation of bugs.
• "bug status" and "bug priority" command let you set a bug's status or priority
• The code was refactored to make it easier to share code between bug-serve (an http implementation of bug) and bug (the commandline implementation)

Still to be done before dropping the "alpha" and releasing v0.1:

• Add "bug relabel" command
• Add "bug milestone" and "bug roadmap" commands
• Fix any issues tagged "bug"

To use this prerelease download the appropriate tarball for your architecture, extract it, and copy the "bug" command somewhere into your $PATH