examples: Add "make local" for direct build against parent biTStream.

This patch adds "make local" target in examples/Makefile. Using this
target examples will be build using biTStream in their parent directory
(not the system wide install). This target simplifies biTSream development
and testing.

examples/Makefile

 # $Id$
 
 CFLAGS = -Wall -O2 -g
+CFLAGS_LOCAL = -Wall -O2 -g -I. -I../..
 LDFLAGS = 
 OBJ = dvb_print_si dvb_ecmg dvb_ecmg_test mpeg_print_pcr rtp_check_seqnum
 
@@ -9,5 +10,8 @@ all: $(OBJ)
 %: %.c
 	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $<
 
+local: CFLAGS = $(CFLAGS_LOCAL)
+local: all
+
 clean:
 	-rm $(OBJ)