Math lib used in all airborne code of paparazzi

HOWTO install a shared library to use in other projects

1. Build library: in this folder, type
  make shared_lib

  the default build directory is var/build/math
  to change it: BUILDDIR=<your_build_dir> make shared_lib

2. Install library: in this folder, type
  make install_shared_lib

  the default install dir is /usr
  and will install files in
  /usr/lib
  /usr/lib/pkgconfig
  /usr/include/pprz

  to change the install dir: PREFIX=<your_install_dir> make install_shared_lib

  note that the default install dir needs root privilege

HOWTO use the shared library

1. with pkg-config --cflags --libs

2. by hand:
  LIBS: -L<prefix>/lib -lpprzmath
  CFLAGS: -I<prefix>/include/pprz


"make clean" will only clean the build directory

