Split apart TIFF generation and datastream storage
Create class for file distribution
Add support for external TIFF storage
Fix image spec to reflect new pyramidal tiff logic
Make base_path easier to use

Sets default to Rails.root/media and uses Pathname object if overridden
to ease the path method
Ignore generated tiffs
Merge pull request #82 from OregonDigital/feature/derivatives-on-file-system

Feature/derivatives on file system