tests: Test MooseFS upgrade

Test gradual upgrade of MooseFS installation to LizardFS.

Tested functionality:
* loading of MooseFS data by LizardFS daemons
* chunk replication between MooseFS and LizardFS chunkservers
* the ability of new and old chunkservers to communicate one with
  another
* LizardFS master compatibility with old chunkservers and mounts
* LizardFS chunkserver compatibility with old mounts

Change-Id: Ida5808d6ad09a4603edce2d51d462531f379d7a8