Resolve #71 by ignoring printf format security warning to worka around compiler error on GCC 4.9

Author: tdicola

setup.py

@@ -54,8 +54,8 @@
       classifiers      = classifiers,
       packages         = find_packages(),
       py_modules       = ['Adafruit_I2C'],
-      ext_modules      = [Extension('Adafruit_BBIO.GPIO', ['source/py_gpio.c', 'source/event_gpio.c', 'source/constants.c', 'source/common.c']), 
-                          Extension('Adafruit_BBIO.PWM', ['source/py_pwm.c', 'source/c_pwm.c', 'source/constants.c', 'source/common.c']),
-                          Extension('Adafruit_BBIO.ADC', ['source/py_adc.c', 'source/c_adc.c', 'source/constants.c', 'source/common.c']),
-                          Extension('Adafruit_BBIO.SPI', ['source/spimodule.c', 'source/constants.c', 'source/common.c']),
-                          Extension('Adafruit_BBIO.UART', ['source/py_uart.c', 'source/c_uart.c', 'source/constants.c', 'source/common.c'])])
+      ext_modules      = [Extension('Adafruit_BBIO.GPIO', ['source/py_gpio.c', 'source/event_gpio.c', 'source/constants.c', 'source/common.c'], extra_compile_args=['-Wno-format-security']), 
+                          Extension('Adafruit_BBIO.PWM', ['source/py_pwm.c', 'source/c_pwm.c', 'source/constants.c', 'source/common.c'], extra_compile_args=['-Wno-format-security']),
+                          Extension('Adafruit_BBIO.ADC', ['source/py_adc.c', 'source/c_adc.c', 'source/constants.c', 'source/common.c'], extra_compile_args=['-Wno-format-security']),
+                          Extension('Adafruit_BBIO.SPI', ['source/spimodule.c', 'source/constants.c', 'source/common.c'], extra_compile_args=['-Wno-format-security']),
+                          Extension('Adafruit_BBIO.UART', ['source/py_uart.c', 'source/c_uart.c', 'source/constants.c', 'source/common.c'], extra_compile_args=['-Wno-format-security'])])