Flight Gear uses the Gnu autoconf and automake tools for managing
Makefiles.  It also uses libtool to manage building shared and static
libraries.  Key input files for this system are:

    configure.in - Top level directory
    Makefile.am - One in each subdirectory
    Include/config.in - input file for building config.h

If you need to modify any of these files, you will need to build and
install the following packages:

    - GNU autoconf 2.12 (available from ftp://prep.ai.mit.edu/pub/gnu)
    - GNU automake 1.2h (available from ftp://ftp.cygnus.com/pub/tromey)

Libtool is not currently used:

    - GNU libtool 1.2   (available from ftp://prep.ai.mit.edu/pub/gnu)
                        (or maybe ftp://alpha.gnu.org/gnu)
    - After upgrading libtool, if we were using it, you would want to run:

      libtoolize --force

When making a change to any of these files you will need to run:

    aclocal ; automake -a ; autoconf

Then follow the regular build procedure:

    ./configure; make; make install

For debuging purposes you might want to try something like:

    CFLAGS=-Wall CXXFLAGS=-Wall ./configure; make; make install

For full optimization using the EGCS compiler on an Intel processor you 
could try something like:

    MACH="-mpentium"   # -m486 -mpentiumpro etc.
    export CC=egcc     # for Linux
    export CFLAGS="-Wall -O5 -fomit-frame-pointer -ffast-math -funroll-loops $MACH"
    export CXXFLAGS="-Wall -O5 -fomit-frame-pointer -ffast-math -funroll-loops $MACH"
    ./configure

