1) Created a subdirectory called 'solaris'. Currently it contains a replica

1) Created a subdirectory called 'solaris'. Currently it contains a replica
   of the 'svr4' directory. However, over time, files in this directory
   will contain the same code as the kernel-portion of pppd in future
   releases of Solaris, hence they most probably will change in contents
   and/or sub-structure.
2) Changed the 'configure' script to not create symbolic link Makefiles
   when the OS is SunOS 4.x. Under 'SunOS' category, only SunOS 5.x (or
   Solaris 2.x) is currently enabled.
3) Changed the rest of the utilities + pppd daemon Makefile.sol2 to point
   to the solaris/Makedefs instead of the one in svr4 directory.