burst_buffer/cray work

Add granularity info to alternate pools
Also change the scontrol show burst buffer format for bb/GRES:
  "  Gres[%d] Name=%s AvailCount=%s UsedCount=%s" to
  "  AltPoolName[%d]=%s Granularity=%s TotalSpace=%s UsedSpace=%s"
  for better consistency with default pool information
Add pool name to burst buffer creation data structures
Create persistent buffer in user-specified pool
Add pool info to allocated buffer table
Fix buffer state load logic, was creating duplicate pool/gres records
bug 2190