Merge branch 'hotfix/0.18.0.12'
Fix translation bug in variable interpolation
Merge remote-tracking branch 'origin/release/0.19'
Move method to model to make it more testable, add spec.
Use path relative to Rails root.
Use request dirs method.
Return a list of all cache directories for the request
Add integration spec.
Merge branch 'hotfix/0.19.0.1' into wdtk