Merge pull request #21 from kpartlow/master

Updated concurrency items and creation of CommandUrls
- Removed 'url' argument from CommandCell.isUrlExpanded() API (uses internal member)
- Minor code clean-up
- TODO:  Need to find referenced cubes in runRuleCube()
- TODO:  Need to support GOTO (RESTART) Rule
- TODO: GroovyUrlClassLoader
updated readme
updated pom.xml version number
[maven-release-plugin] prepare release 2.6.0.201406051158
[maven-release-plugin] prepare for next development iteration
Updated concurrency test to better test the concurrency issue we would've had.