Arakoon 1.9.17

Changes:

• store & verify cluster_id in store ( #170 )
• local collapse cleans up files, even if there's nothing to collapse ( #160 )
• fix --copy-db-to-head cli ( #168 )
• dependencies:
  • core.114.35+03 => core.v0.9.114.41+37
  • lwt.2.7.0 => lwt.3.0.0