Fix including functions.sh when using dash not bash.

Change-Id: I4a841edd8f6ad169fdac6e99960ce71e09e6469c
Reviewed-on: http://gerrit.dmdirc.com/51
Reviewed-by: Gregory Holmes <greboid@dmdirc.com>
Tested-by: Gregory Holmes <greboid@dmdirc.com>

installer/linux/getjre.sh

 fi;
 
 if [ -e "functions.sh" ]; then
-	. functions.sh
+	. `dirname $0`/functions.sh
 else
 	echo "Unable to find functions.sh, unable to continue."
 	exit 1;

installer/linux/installjre.sh

 ISFREEBSD=`uname -s | grep -i FreeBSD`
 
 if [ -e "functions.sh" ]; then
-	. functions.sh
+	. `dirname $0`/functions.sh
 else
 	echo "Unable to find functions.sh, unable to continue."
 	exit 1;

installer/linux/setup.sh

 fi;
 
 if [ -e "functions.sh" ]; then
-	. functions.sh
+	. `dirname $0`/functions.sh
 else
 	echo "Unable to find functions.sh, unable to continue."
 	exit 1;

installer/linux/uninstall.sh

 JAVA=`which java`
 
 if [ -e "functions.sh" ]; then
-	. functions.sh
+	. `dirname $0`/functions.sh
 else
 	echo "Unable to find functions.sh, unable to continue."
 	exit 1;

launcher/unix/DMDirc.sh

 done;
 
 if [ -e "functions.sh" ]; then
-	. functions.sh
+	. `dirname $0`/functions.sh
 else
 	# TODO: Remove this and depend on functions.sh...
 	echo "Unable to find functions.sh, using old functions"
 	cat <<EOF> ${launcherUpdater}
 		cd `dirname $0`
 		if [ -e "functions.sh" ]; then
-			. functions.sh
+			. `dirname $0`/functions.sh
 		else
 			# TODO: Remove this and depend on functions.sh...
 			echo "Unable to find functions.sh, using old functions"