Created value class Variance.
Created value class Variance.

This will be instead of passing numbers like -1 and 1 around,
also instead of a variety of named constants like AnyVariance
and CoVariance, and also instead of sometimes using the flags
Flag.COVARIANT and Flag.CONTRAVARIANT for things.

1, 2, 3, go-type-safety-rah!

slothspot/scala,jvican/scala,jvican/scala,lrytz/scala,shimib/scala,jvican/scala,scala/scala,lrytz/scala,shimib/scala,shimib/scala,martijnhoekstra/scala,lrytz/scala,felixmulder/scala,slothspot/scala,felixmulder/scala,scala/scala,jvican/scala,lrytz/scala,shimib/scala,shimib/scala,felixmulder/scala,shimib/scala,scala/scala,martijnhoekstra/scala,slothspot/scala,martijnhoekstra/scala,scala/scala,felixmulder/scala,jvican/scala,felixmulder/scala,lrytz/scala,martijnhoekstra/scala,scala/scala,martijnhoekstra/scala,slothspot/scala,felixmulder/scala,jvican/scala,felixmulder/scala,slothspot/scala,jvican/scala,scala/scala,lrytz/scala,slothspot/scala,slothspot/scala,martijnhoekstra/scala