Ability to use the ISR( PCINT0_vect )?

[MikeX7]

This isn't really a bug, but rather a request to solve a problem which TinyWire presents, when you need to use the PCINT interrupts yourself.

I need to use PCINT interrupts on pins P3 and P4, but I cannot declare ISR( PCINT0_vect ){} in my sketch, because TinyWire has already declared it.
So it would be nice to have some way to perhaps tell the TinyWire that you wish to enable PCINT interrupts on additional pins (I think it only enables it on the SDA pin by default) and then supply TinyWire with a callback function which it calls when ISR( PCINT0_vect ) occurs, so I can execute some of my code as well during the interrupt.

I am not sure if this library is still actively developed, but it am using it as pure slave and it works great, while being simple to use.
This is the only feature I am missing from it.

[pilotak]

In case somebody finds this, here is an updated the code that provides a callback when PCINT0_vect is called
https://github.com/pilotak/TinyWire