Moving core functionality into the buildjs.core module
More core integration
Updated underscore version
Fix local and class reference to regexes, change to patterns
Reinstate parallel execution tasks for local files
Bump version to 0.5.0
Bump version to 0.5.1
Tweaked plugin loading behaviour
Updated rigger-collate tests to include option parsing
Updated package versions of plugin modules
Bump version to 0.5.2
Merged 0.5.x into master