Extract BATS SoupTCP file support

Make it independent of BATS PITCH 1.12.0 so that it can be utilized by
other protocol versions and other protocols.

Signed-off-by: Jussi Virtanen <jussi.virtanen@valotrading.com>
Change BATS PITCH 1.12.0 specific message parser into object

Signed-off-by: Jussi Virtanen <jussi.virtanen@valotrading.com>
Merge pull request #144 from jvirtanen/features/bats-souptcpfile

Extract BATS SoupTCP file support

Make it independent of BATS PITCH 1.12.0 so that it can 
be utilized by other protocol versions and other protocols.