Resolves bugzillas: #213533, #216092, #220211, #223002, #223234/#223240
    
    Detailed comments:
    
    * Lock in memory to prevent being swapped out
    * Turn on RR scheduling for main + score threads
    * Let qdiskd wait for CMAN to start
    * Add option to qdiskd to stop CMAN if qdisk device is not available
    * Make qdisk interval timings more accurate
    * Add option to reboot node if qdiskd detects internal hang > failure time (e.g. interval*tko, in seconds)
    * Add per-heuristic tko counts for unreliable heuristics (e.g. ping packets)
    * Remove nodes from quorate mask immediately on eviction
    * Update man pages with better examples
    * Don't let >1 instance of qdiskd be started
    * Clarify logging output.
    * Improve data in status_file.
    * Allow qdiskd to run with no defined heuristics (master-always-wins mode).
    * Make fencing of nodes optional (default = on).
    * Make sure CMAN is running before we try to talk to it at each point.