OSX keyboard driver is missing support for the numeric pad "fullstop" key and the (EU) section sign (§) key

[dionoid]

While the keyboard drivers for Windows, Linux, X and SDL map the numeric keypad's period/fullstop/delete key to ALLEGRO_KEY_PAD_DELETE, the OSX driver maps it to ALLEGRO_KEY_FULLSTOP. I think this is incorrect and makes it impossible to distinguish between the period/fullstop key on the main keyboard and the one on the numeric keypad.

My suggestion is to map this key on OSX to ALLEGRO_KEY_PAD_DELETE, the same way as the other OS's do.

Also on OSX, the Section Sign key (§) - which on European Mac keyboards is located below the Escape key - isn't currently mapped.

My suggestion is to map this key to ALLEGRO_KEY_UNKNOWN+0, so al least its key press can be handled.

I'll create a PR if that's OK.

[torhus]

For the record the key below Esc is mapped to TILDE for the US layout, and BACKSPACE with Norwegian layout on my Norwegian keyboard. This is on Windows. Someone with a US keyboard would have to verify the first one, but backspace makes little sense to me. The characters on that key are `~ in US layout, |§ in Norwegian.