* Added new thumbnail method to create cropped rectangle thumbnails. (pil error for portrait pictures left.)
* Changed stylesheets, to display the thumbnails in a fluid way.
Replaced thumbnail method.
Added media queries for the fluid thumbnail display.
Merge branch 'feature/fluid-thumbnails' into develop
Cleanup: Removed unneeded return values from create thumbnail method.
Cleanup: Removed superfluous imports in models.py
Added zip file for download to not encrypted albums.
Addes styles for download link.
Merge branch 'feature/album_zip_file' into develop
Moved album generation to album class
Added Workaround for copytree problem. (Assets are copied by copytree at a moment where the destination directory should already exist while copytree demands that the destination directory, must not already exist.)
Merge branch 'feature/move_album_generation_in_album_class' into develop
Renaming the ‘_assets_for_all_themes’ to ‘crypto’ (As these assets are doing the crypto part.)
Cleanup in requirements.txt (sorted alphabetically)
Added info file processing, adjusted album initialization accordingly and removed album-name argument from the command line interface.
Merge branch 'feature/album-info-file' into develop
Merge pull request #3 from chrK/develop

Changed gallery layout: Fluid square thumbnails.