Fix for broken MACAddress::findAllAddresses

The current JUCE code only finds the active network interface MAC address.

The following code finds every network interface and gives its MAC:

#include <stdio.h>    //printf
#include <string.h>    //strncpy
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>    //ifreq
#include <ifaddrs.h>    //ifreq
#include <unistd.h>    //close
void findAllAddresses (Array<MACAddress>& result)
    struct ifreq ifr;
    struct ifaddrs * addrs = 0;
    if (getifaddrs(&addrs) == -1) return;
    const int s = socket (AF_INET, SOCK_DGRAM, 0);
    if (s == -1) 
    struct ifaddrs * thisaddr = addrs;
    while (thisaddr)
        ifr.ifr_addr.sa_family = AF_INET;
        strcpy(ifr.ifr_name, thisaddr->ifa_name);
        if (0 == ioctl(s, SIOCGIFHWADDR, &ifr))
            MACAddress ma ((const uint8*) ifr.ifr_hwaddr.sa_data);
            if (! ma.isNull())
                result.addIfNotAlreadyThere (ma);
        thisaddr = thisaddr->ifa_next;

Cool, thanks very much, I'll take a look asap!