[BUILD] Add generic Makefile.rules
Make the STM32 Makefile.includes usable from outside the examples tree (Issue #28)
[BUILD] Generate *.MAP files

Reworked by: Frantisek Burian <BuFran@seznam.cz>
Modify all of the examples to use the Makefile.rules
[FLASH:OPENOCD] Fixed the flashing function
[BUILD] Add source library path to the examples makefile to override default paths
[BUILD] Splitted long lines in targets definition
[BUILD] Removed TOOLCHAIN_DIR, add autodetection of current libopencm3 library placement
[FIX] Correct the compilation of C++ files (prepared for the future)
[BUILD] Move out ARCH_FLAGS from the LDFLAGS and CFLAGS, CXXFLAGS
[FIX] Library paths and preprocessor defines should be in CPPFLAGS, Reorganization of *FLAGS

Using:
http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#Warning-Options
http://gcc.gnu.org/onlinedocs/gcc/Preprocessor-Options.html#Preprocessor-Options
http://gcc.gnu.org/onlinedocs/gcc/Link-Options.html#Link-Options
http://gcc.gnu.org/onlinedocs/gcc/ARM-Options.html#ARM-Options

To CFLAGS are added only -ffunction-sections -fdata-sections, so this should not break the build.
[BUILD] Use the automatic variable RM=rm -f