Changes list priority from int to double.

This allows an easy implementation of something like A* in work queue,
while preserving the old int behaviour.
Deprecates specify_task_order.

We could not gurantee the given policy. With the addition or
specify_priority, the queue works as if FIFO was specified.
If connection fails during auth, retry.

chirp_client_connect would treat any failure during authentication as EACCES
which would prevent chirp_reli from retrying. This caused the chirp tool to
fail for Anna/Charles in their experiments.

This commit also adds failure checking for all link calls.
Bump to 4.3.0rc1pre-parrot
Print priority on wq-status
Bump to 4.3.0rc2pre-parrot
Fix priority python binding.
Bump to 4.3.0rc3