Improve compatibility with Arduino building

[fabianoriccardi]

Hi,
I've observed a different behaviour between Arduino IDE compilation and your makefile.
Arduino IDE seems to compile only *.c/.cpp in sketch root folder andin src/(recursively) folder.
Your makefile compiles everything recursively starting from sketch root.

Is it possibile to emulate the Arduino behaviour?

I've also tried:
EXCLUDE_DIRS = $(SKETCH_DIR)/foo
to exclude a file foo/bar.cpp, but it doesn't do anything (i.e. foo/bar.cpp is compiled as usual)

[plerup]

Try using:
EXCLUDE_DIRS=./foo