Some layouts are not compatible with KLE schema

[adamws]

During parsing of all layouts, I found following problems:

• some of the boards uses illegal color values, I already submitted Fix illegal color values #2133 to address that
• owlab/spring/spring.json uses illegal rotations, according to https://github.com/ijprest/kle-serial/blob/master/index.ts#L148 it can be specified only on the first key in a row - this layout can't be loaded with keyboard-layout-editor website:

Error: 'r' can only be used on the first key in a row:
  {r:12,y:-0.8,x:0.1}

• couple of rart boards use illegal labels, for example rart75 defines following key: 0,15\n\n\n3,1\n\n\n\n\n\n\n\n\ne0 - there can be maximum of 12 labels ('\n' separated items) - loading this layout with KLE website will result in truncated labels and 'e0' won't be displayed:
  
  to have center label displayed it should be defined as 0,15\n\n\n3,1\n\n\n\n\n\ne0 instead.

Fix for last point is rather simple and intent of an author is clear. I did not analyze the impact of this minor incompatibilities on via itself.