Fixes SI-6521, overrides Range#head to be faster
Fixes SI-6521, overrides Range#head to be faster

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