Add the ability to configure avrdude options

A new environmental variable AVRDUDE_OPTS is added, which can be used to
configure the options passed to avrdude.

Fix #53

HISTORY.md

@@ -7,6 +7,7 @@ The following is the rough list of changes that went into different versions. I
 - Replace hardcoded executables with variable
 - Fix whitespace issues
 - Add a warning when HEX_MAXIMUM_SIZE is not specified
+- Add the ability to configure avrdude options. Fix issue #53
 
 ### 0.10.6 (2013-06-14)
 - Fix whitespace and add /dev/null redirection (https://github.com/sej7278)

arduino-mk/Arduino.mk

@@ -798,7 +798,12 @@ ifndef AVRDUDE_CONF
     # If avrdude is installed separately, it can find its own config file
 endif
 
-AVRDUDE_COM_OPTS = -q -V -p $(MCU)
+# Default avrdude options. -V Do not verify, -q - suppress progress output
+ifndef AVRDUDE_OPTS
+    AVRDUDE_OPTS = -q -V
+endif
+
+AVRDUDE_COM_OPTS = $(AVRDUDE_OPTS) -p $(MCU)
 ifdef AVRDUDE_CONF
     AVRDUDE_COM_OPTS += -C $(AVRDUDE_CONF)
 endif