Support cropping suffixes

[s2b]

Currently, the ImageViewHelper only partially supports the c and m suffixes for manually specified height and width.

One possible solution could be to convert the specified values to a crop area object.

[DanielRuf]

Currently, the ImageViewHelper only partially supports the c and m suffixes for manually specified height and width.

This is not quite clear to me. So we can we use a value like 800c instead of 800 or does this not work with your viewhelper (sms namespace)?

[s2b]

Currently, the specified width will be applied to the fallback image only, the height will be skipped completely. So no, it is not safe to use those parameters with my ViewHelpers.

The problem is that supporting these values would lead to a bunch of complicated edge cases which I wasn't able to solve yet.

[NiklasLazinbee]

I think it fits in with this issue: the height specifications are apparently not supported. Normally I can write in fluid:
<f:image src="{image.originalResource.publicUrl}" width="314" maxHeight="400"/>

If I have a portrait format, the image will be rendered up to a maximum of 400.
This could be a helpful feature.