Make serial baudrate detection work in Mac

Replace regex used for detecting serial baudrate.
New regex is tested in both debian and mountain lion.

fix #52 - serial monitor baudrate detection

HISTORY.md

@@ -6,6 +6,7 @@ The following is the rough list of changes that went into different versions. I
 ### 0.10.6 (in development)
 - Fix whitespace and add /dev/null redirection (https://github.com/sej7278)
 - Change the way AUTO_ARDUINO_VERSION is computed (https://github.com/sej7278)
+- Make serial monitor baudrate detection work in Mac as well(https://github.com/sej7278)
 
 ### 0.10.5 (2013-06-11)
 - Add USB_VID and USB_PID to CPPFLAGS only if the board is Leonardo.

arduino-mk/Arduino.mk

@@ -559,9 +559,7 @@ endif
 # for more information (search for 'character special device').
 #
 ifndef MONITOR_BAUDRATE
-    # This works only in linux. TODO: Port it to MAC OS also
-    # https://github.com/sudar/Arduino-Makefile/issues/52
-    SPEED = $(shell grep --max-count=1 --regexp="Serial.begin" $(LOCAL_PDE_SRCS) $(LOCAL_INO_SRCS) | sed -e 's/\t//g' -e 's/\/\/.*$$//g' -e 's/(/\t/' -e 's/)/\t/' | awk -F '\t' '{print $$2}' )
+    SPEED = $(shell egrep -h 'Serial.begin\([0-9]+\)' $(LOCAL_PDE_SRCS) $(LOCAL_INO_SRCS) | sed -e 's/[^0-9]//g'| head -n1)
     MONITOR_BAUDRATE = $(findstring $(SPEED),300 1200 2400 4800 9600 14400 19200 28800 38400 57600 115200)
 
     ifeq ($(MONITOR_BAUDRATE),)