alloc doesn't take a refdb; git_refdb_free nicely in the tests
Merge pull request #1491 from ethomson/backends_dont_refdb

alloc doesn't take a refdb
Plug a couple of leaks
start breaking everything
Write out multivar remote config
Transform remote.c
push.c compiles
mostly working
config: allow setting multivars when none exist yet

Adding a multivar when there are no variables with that name set
should set the variable instead of failing.
Save the right refspecs
don't leak specs
fixup! config: allow setting multivars when none exist yet