Make sure OSX build uses bash 4+

Author: facchinm

build.conf

@@ -1,5 +1,5 @@
 AVR_VERSION=3.6.1
-BUILD_NUMBER=arduino1
+BUILD_NUMBER=arduino2
 
 AVR_SOURCES="http://distribute.atmel.no/tools/opensource/Atmel-AVR-GNU-Toolchain/${AVR_VERSION}"
 ATMEL_PACKS_SOURCES="http://packs.download.atmel.com/"

package-avr-gcc.bash

@@ -99,7 +99,7 @@ rm -rf objdir/{info,man,share}
 
 if [[ -f ${ATMEL_ATMEGA_PACK_FILENAME}.atpack ]] ; then
 #add extra files from atpack (only if the package is altrady there)
-./atpack.build.bash
+${BASH} ./atpack.build.bash
 fi
 
 # if producing a windows build, compress as zip and