Update needed for Xdebug 2.3

[derickr]

Hi!

Thanks for writing the this helper!

With Xdebug 2.3 comes support for shared secret triggers to enable
profiling and tracing. So instead of just sending "1" as the value for
the cookies for XDEBUG_TRACE and XDEBUG_PROFILE, you now need to be able
to set it to the value that you can (optionally) configure through
xdebug.trace_enable_trigger_value and
xdebug.profiler_enable_trigger_value . This means that your extension
needs to support setting these values, similarly as what you need to do
for the idekey already. Can you please add that, so users can use the helper
with these trigger values? Let me know if you have any
questions.

cheers,
Derick