Added ReadMe and LGPL files

Signed-off-by: pjs <pjs@alum.mit.edu>

ReadMe.1st

+SimpleKit-ruby is a minimalist Ruby library which implements discrete event
+simulation using event graphs.
+
+Copyright (C) 2012  Paul J. Sanchez
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License as published by the Free Software Foundation; either
+version 2.1 of the License, or (at your option) any later version.
+
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License in the file lgpl.txt along with this library; if not, write
+to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+Boston, MA  02111-1307  USA
+
+DESCRIPTION
+
+SimpleKit-ruby is a very minimal Ruby implementation of discrete event
+simulation based on Lee Schruben's "Event Graph" approach.  I wrote it
+to illustrate to CS students how simulation works.  You are welcome to
+use it as long as you clearly understand that it was designed as a
+teaching tool.  For serious simulation modeling with event graphs I
+recommend Lee Schruben's SIGMA package or Arnie Buss's SimKit.
+
+WHAT'S WHAT
+
+This top level folder contains this file, "ReadMe.1st", and a copy of the
+GNU Lesser General Public License (LGPL) in the file "lgpl.txt".  Please
+read the LGPL to see what your rights and restrictions are!
+
+There are two subdirectories.  Source code for SimpleKit-ruby can be found
+in lib/simplekit.rb.  Documentation can be generated using Ruby's
+rdoc command.
+
+The second subdirectory is "demos", and contains three simple models to
+illustrate SimpleKit-ruby usage.  "MyModel.rb" demonstrates basic event
+scheduling and halting the model.  "MyModelArgs.rb" uses random times
+for the event scheduling, and shows how to schedule with arguments for
+the event methods.  Finally, "MMk.rb" implements an M/M/k queueing
+model.