kaleidoscope-builder: Pull VID, SKETCH_PID and BOOTLOADER_PID from boards.txt

Instead of hardcoding defaults for `VID`, `SKETCH_PID`, and `BOOTLOADER_PID`,
use `arduino-builder -dump-prefs` to pull these out of `boards.txt`.

Signed-off-by: Gergely Nagy <algernon@keyboard.io>

etc/kaleidoscope-builder.conf

@@ -10,10 +10,6 @@ LIBRARY="${LIBRARY:-${SKETCH}}"
 ######## Keyboard hardware definitions
 ########
 
-# These should be pulled from Arduino boards.txt
-VID="${VID:-1209}"
-BOOTLOADER_PID="${BOOTLOADER_PID:-2300}"
-SKETCH_PID="${SKEYCH_PID:-2301}"
 BOARD="${BOARD:-model01}"
 MCU="${MCU:-atmega32u4}"
 if [ "${BOARD}" = "virtual" ]; then
@@ -32,8 +28,21 @@ fi
 # Shamelessly stolen from git's Makefile
 uname_S=$(uname -s 2>/dev/null || echo not)
 
+find_device_vid_pid() {
+  VPIDS=$(${ARDUINO_BUILDER} \
+		          -hardware "${ARDUINO_PATH}/hardware" \
+		          -hardware "${BOARD_HARDWARE_PATH}" \
+		          ${ARDUINO_TOOLS_PARAM} \
+		          -tools "${ARDUINO_PATH}/tools-builder" \
+		          -fqbn "${FQBN}" \
+              -dump-prefs | grep "\.[vp]id=")
+  VID=${VID:-$(echo "${VPIDS}" | grep build.vid= | cut -dx -f2)}
+  SKETCH_PID=${SKETCH_PID:-$(echo "${VPIDS}" | grep build.pid= | cut -dx -f2)}
+  BOOTLOADER_PID=${BOOTLOADER_PID:-$(echo "${VPIDS}" | grep bootloader.pid= | cut -dx -f2)}
+}
 
 find_device_port() {
+  find_device_vid_pid
 	DIR=$(dirname "$(readlink -f "$0")")
 	DEVICE_PORT_PROBER="${DIR}/find-device-port-linux-udev"
 	DEVICE_PORT="$(perl ${DEVICE_PORT_PROBER} ${VID} ${SKETCH_PID})"
@@ -49,6 +58,7 @@ reset_device_cmd() {
 MD5="md5sum"
 
 find_bootloader_ports() {
+  find_device_vid_pid
 	DIR=$(dirname "$(readlink -f "$0")")
 	DEVICE_PORT_PROBER="${DIR}/find-device-port-linux-udev"
 	DEVICE_PORT_BOOTLOADER="$(perl ${DEVICE_PORT_PROBER} ${VID} ${BOOTLOADER_PID})"