Expand COMPILING and setup_env.py to be even more userfriendly

COMPILING

@@ -8,9 +8,16 @@ react   0.9.2
 camlbz2 0.6.0    
 
 
-we provide a script that sets up the development the prerequisites:
+we provide a script that sets up the development prerequisites:
   python tools/setup_env.py
 
+You can tweak the features/dependencies of the development prerequisites with
+command line arguments to the tools/setup_env.py script. Check out:
+  python tools/setup_env.py --help
+
+Note that when the tools/setup_env.py script has finished, it outputs some
+commands for you to run in your shell!
+
 COMPILING:
 
 we use ocamlbuild combined with ocamlfind as main driver for our builds.

tools/setup_env.py

@@ -284,6 +284,16 @@ def install_libbz2():
     lib.sh(['make', '-f', 'Makefile-libbz2_so'])
     lib.sh(['cp', 'libbz2.so.1.0.6', '%s/lib' % PREFIX])
 
+def print_env_setup_help():
+        print
+        print
+        print 'Now execute these statements in your shell to enable your ' \
+                'build env:'
+        print 'export OCAML_HOME=%s' % PREFIX
+        print 'export LIBRARY_PATH=${LIBRARY_PATH}:${OCAML_HOME}/lib'
+        print 'export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:${OCAML_HOME}/lib'
+        print 'export PATH=${PATH}:${OCAML_HOME}/bin'
+
 def do_it():
     fine = maybe_clean()
     if not fine:
@@ -305,9 +315,10 @@ def do_it():
         if options.bisect:
             install_bisect()
         #sudo cp lablgtk-2.14.2/examples/test.xpm /usr/share/pixmaps/ocaml.xpm
-        print '\n\nnow prepend %s/bin to your PATH' % PREFIX
+        print_env_setup_help()
     else:
         print "setup_env.py:  quick-check tells me we're fine (%s)" % PREFIX
+        print_env_setup_help()
 
 
 if __name__ == '__main__':