Verify packet intergrity with prefix / suffix

We had some weird issues with php only sending partial packets,
so now we are optionally allowing packets to be wrapped in (,).

If one is detected, the other must exist or a failure is reported.
Packet Integrity: add comment and fix bug.

The function is supposed to return the trimmed message.
Merge verify-packets (#3) into master

Verify packet intergrity with prefix / suffix

We had some weird issues with php only sending partial packets,
so now we are optionally allowing packets to be wrapped in (,).

If one is detected, the other must exist or a failure is reported.