New features

[gorgiaxx]

1. Single session mode (by @imbeee)
2. Custom headers.
3. Optional buffer size.
4. Optional url check.
5. Payloads can be selected between URL parameters and Request headers.

[ghost]

@gorgiaxx thank you for your PR, could tell me which version of php works tunnel.nosocket.php? In my hosting with php 7 stuck on main loop, in connect command and can't retrieve data from other commands.

[L-codes]

Neo-reGeorg realize the above function