stream: add option to disable raw reassembly

stream: add option to disable raw reassembly

Raw reassembly is used only by the detection engine. For users only
caring about logging it's a significant overhead, both in cpu and
memory usage.

The option is called 'raw' and lives under the stream.reassembly
options.

stream:
  memcap: 32mb
  checksum-validation: yes      # reject wrong csums
  inline: auto                  # auto will use inline mode in IPS mode, yes or no set it statically
  reassembly:
    memcap: 64mb
    depth: 1mb                  # reassemble 1mb into a stream
    toserver-chunk-size: 2560
    toclient-chunk-size: 2560
    randomize-chunk-size: yes
    #randomize-chunk-range: 10
    raw: false # <- new option