Updated revisions log
Signed drivers for Windows 8.1
Signed drivers for Windows 8.1

Merge tag '1.0.5-r2' into HEAD

Conflicts:
	build/shared/revisions.txt
	build/windows/dist/drivers/arduino.cat
Merge tag '1.5.5-r2' into ide-1.5.x

Conflicts:
	build/shared/revisions.txt
	build/windows/dist/drivers/arduino.cat
Make some operators in IPAddress const

These functions do not modify the IPAddress object, but were not marked
as const. This meant that you could not do:

void set_ip(const IPAddress& ip) {
	uint32_t copy = ip;
}

Since calling operator uint32_t() on ip would discard the constness of
the reference.