[Boost.Build] system update

From: David Abrahams (david.abrahams_at_[hidden])
Date: 2001-12-16 13:03:52

This is not an update of the Boost.Jam executable; just the build system
files:

tools/build/boost-base.jam

     * Handle different spellings of the PATH environment variable
       for Windows

     * Ungristed elements of a target's requirements are now
       treated as rules which transform the target's property set.
       The rules must have the following signature:

        transform-properties ( toolset variant : properties * )

     and should return the new property set.

     * Added target name adjustment feature for Python debugging targets.

tools/build/borland-tools.jam
tools/build/gcc-tools.jam
tools/build/intel-linux.jam
tools/build/metrowerks-tools.jam
tools/build/msvc-tools.jam
tools/build/mingw-tools.jam

     * Adjustments to better support Python targets

tools/build/python.jam

     * Lots of adjustments for building / testing Python targets:
        PYTHON_LAUNCH variable prefixes Python executable name
                 -- can be used to invoke debugger.
        PYTHON_ARGS variable postfixes Python executable name
        CYGWIN_ROOT variable can be used to specify root of cygwin
installation

===================================================
  David Abrahams, C++ library designer for hire
 resume: http://users.rcn.com/abrahams/resume.html

        C++ Booster (http://www.boost.org)
          email: david.abrahams_at_[hidden]
===================================================