[meta-beagleboard] Proposal to alter LED activity during BeagleBone Black flashing

Koen,

Please review the following pull request:
https://github.com/beagleboard/meta-beagleboard/pull/7

The only delta is:
contrib/bone-flash-tool/emmc.sh
@@ -5,6 +5,9 @@

export PATH=$PATH:/bin:/sbin:/usr/bin:/usr/sbin

+# Indicate that the script is running by changing away from heartbeat on USR0
+echo timer > /sys/class/leds/beaglebone\:green\:usr0/trigger