Merge tag '0.6.0-beta.3' into develop

pallet-lein-0.6.0-beta.3
Updated version for next release cycle
Update leiningen/pallet.clj for next release cycle
After release, commit updated source file

The release updates the files for the next release cycle.
Fix enforcement of either ws or xpcom
Updated project.clj, release notes and readme for 0.6.0-beta.4
Merge branch 'release/0.6.0-beta.4'