Add getClassloader method on KernelHelper Class
Add getRequest method to KernelHelper Class
Add CacheRebuildCommand class
Replace keyword _content with _controller
Update Controller return render array
Merge pull request #239 from jmolivas/beta-4-generate-controller

Beta 4 generate controller
Merge pull request #240 from jmolivas/add-cache-rebuild-command

Add cache rebuild command
Update supported version beta4
Add cache:rebuild command
Merge pull request #241 from jmolivas/update-readme-beta-4-cache-rebuild

Update readme beta 4 cache rebuild