2.5.8 - Critical bugfix for non-windows users

Somehow, at some point (not sure exactly when or how) avrdude.pattern.program got changed to avrdide.pattern.program.windows, leaving other OS's out in the cold. Since I don't have non-windows systems to test on, and most people use SerialUPDI which is unaffected, it had gone unnoticed. This prevented users on effeced operating systems from uploading using any tool other than SerialUPDI (but not bootloading or uploading through a bootloader, just uploading to parts without a bootloader (or "upload using programmer" - but that generates an error intentionally, because doing that on a bootloader board is guaranteed not to work).

This also fixes installation for users on 32-bit linux, and responds to Wire as master trying to write more data than will fit in the buffer sending BUFFER_LENGTH bytes, instead of (size of data that was to be written) modulo BUFFER_LENGTH..