v0.8.6, ui improvements, ES transport compression, fixed traffic over reporting

  - Deal with non data ES nodes
  - Viewer prints error if it can't find pcapDir setting
  - New setting dbFlushTimeout that controls how often we flush to ES
  - New setting compressES that turns on compresesion to ES, requires
    http.compression: true in elasticsearch yml file
  - libnids was overreporting traffic, switch to libpcap stats,
    bytes/sec and total bytes/sec in stats will be lower
  - Fixed recent jade warnings
  - Fixed openned export
  - minor ui improvements