destiny: wireshark compliant tcp flags
This enum is also used to set the tcp flags within a tcp header.
With the current values in this enum, wireshark is not able to
recognize the tcp segments as their actual tcp type,
and thus odd messages in wireshark appear.

destiny: reusing tcp flags for combinations
Merge pull request #1275 from cgundogan/fix_tcp_flags_for_wireshark

destiny: wireshark compliant tcp flags