Release Control Support Makefiles

  These makefiles provide a framework for building third-party source
projects in Release Control.  The original sources can be placed in
a subdirectory of the actual project and wrapped with a simple makefile
that builds it with the proper options.

  Common.make provides basic functionality following the RC makefile
API rules.  It implements the installsrc and clean targets and defines
the dependancies between the all the standard targets, including build
and install.

  GNUSource.make implements the build and install targets for sources
which use GNU autoconf's configure script to build.

  BSDSource.make implements the build and install targets for sources
which use BSD makefiles to build.