add timeout to I2C calls

[PocketPi]

I would love to have an option for timeout in the I2C calls.

Generally I find it bad when code can stall in a while(1) loop.

[AndreCostaaa]

This has also bothered me recently.
How about a pointer to, let's say a 8 bit map, that we can set so the user can check for it in case he's interested ?
As a bonus we could also make the function return a boolean value (right now it has void as its return type)

I'll open a PR with this proposal

[mindnever]

My solution to this issue was to add weak function (i2c_is_timed_out() for example) that returns true to use instead of while(i2c_nack(i2c)) - while(i2c_nack(i2c) && !i2c_is_timed_out()) .. This by default does not change the behaviour, but if provided by user code, can check for whatever timeout or other condition to break the loop.
Obviously, the function does take some parameter to identify which i2c peripheral is in use, but thats implementation specific in my case.