Subject: [PATCH 3/9] refs/reftable: skip duplicate name checks

I can't remember why I did not rely on the available routine (did it not exist at the time? or maybe I assumed the files backend relied on the file system to enforce well-formedness). If the functionality is covered by refs_verify_refname_available, it's probably better to rip out of the reftable library (essentially, just delete refname.c and friends) rather than disable it. I am assuming libgit2 will have an equivalent routine as well.