Option rework

[loicsapone]

This is the rework of the option class. The main idea is to have one class per option, and that each class carries the URL construction and Symfony YAML configuration.

This is a work in progress. I think the simple options (height, width, rotate,...) are fine as I've done them, but there's still the imgproxy “meta options” (e.g. resize). I'd like these “meta options” to be based on the simple options to avoid duplicating code, but I haven't figured out how to do it properly yet.

If anyone has any ideas, I'd love to hear them.

[loicsapone]

Oh, and I forgot to mention it, but it's a BC break: options will be less verbose, so YAML configuration in Symfony projects may break

For example, in the case of the rotate option, the YAML configuration will change as follows:

# before 
presets:
  plain_thumbnail:
    options:
      rotate: 
        angle: 90

# after
presets:
  plain_thumbnail:
    options:
      rotate: 90