Remove tools/test-renamer
Remove tools/test-renamer

It delivered us the terser 't1234' naming convention for test
cases. Its work is done.

This commit does the bidding of the script's author:

> Despite its shameful hackiness, checked in for posterity.
> It'll live on forever in the git history; then I can remove it.

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