Commercial comps tweaks2

This tidies up a load of small issues with Masterclasses and Soulmates.

Widths are now calculated when using 1/3 & 2/3, makes it far better than 33% & 66%.

Mixins made for duplicated code used in Masterclasses component.
Cool with me if we don't load SVG in Android 2.1 and 2.3. I thought we did, my bad, then!