Make files for ANTLR-2.6.1

As of now, ANTLR only comes with source files...no make file.  These make files
are so ANTLR can be built as a standalone library under various platforms.

Instructions
   -Copy Makefile* to the 'ANTLR-2.6.1/cpp' folder.

NOTE:
   Some compilers, namely gcc (atleast under Linux) doesn't have the istream
   header file.  It has an istream.h file however.  Included in this directory
   is an istream include file that should be placed in your ANTLR-2.6.1/cpp
   folder.