C++: all: Makefile: fixes for cross-compilation

Makefile's target for dependencies was added and all of the pigpio
relations in Makefiles were changed. Now it can be easily compiled or
cross-compiled with all dependencies by running only "make".

Author: corteccia

C++/Examples/RCInput/Makefile

@@ -1,15 +1,15 @@
 CXX ?= g++
 NAVIO = ../../Navio
 
-PIGPIO_PATH := $(PIGPIO_PATH)
+PIGPIO_PATH ?= $(NAVIO)/pigpio
 
 LIB = -L$(PIGPIO_PATH)
 
 INCLUDES = -I ../../Navio -I$(PIGPIO_PATH)
 
 all:
 	$(MAKE) -C ../../Navio all
-	$(CXX) -std=gnu++11 $(INCLUDES) $(LIB) RCInput.cpp -L$(NAVIO) -lnavio -o RCInput -lrt -lpthread -lpigpio || $(MAKE) pigpio
+	$(CXX) -std=gnu++11 $(INCLUDES) $(LIB) RCInput.cpp -L$(NAVIO) -lnavio -o RCInput -lrt -lpthread -lpigpio
 
 clean:
 	rm -f RCInput

C++/Navio/Makefile

@@ -1,14 +1,21 @@
 CXX ?= g++
-CFLAGS = -std=c++11 -Wno-psabi -c -I .
+PIGPIO_PATH ?= pigpio
+CFLAGS = -std=c++11 -Wno-psabi -c -I . -I$(PIGPIO_PATH)
 
 SRC=$(wildcard */*.cpp)
 OBJECTS = $(SRC:.cpp=.o) 
 
 %.o: %.cpp
 	$(CXX) $(CFLAGS) -o $@ $< 
 
-all: $(OBJECTS)
+.PHONY: get_deps clean
+
+all: get_deps $(OBJECTS)
 	ar rcs libnavio.a $(OBJECTS)
 
+get_deps:
+	bash get_dependencies.sh
+
 clean:
 	rm -f */*.o *.a
+	$(MAKE) -C pigpio clean