Add GEM_PATH to include path.

If Gem is available add its path to the include path to ensure that
classes from gems will be navigatable. 

Change-Id: Ic7be3d3ccc350954f8f5f32f4d216eaf668ea084
Signed-off-by: Alexander Kurtakov <akurtako@redhat.com>
diff --git a/plugins/org.eclipse.dltk.ruby.launching/scripts/path.rb b/plugins/org.eclipse.dltk.ruby.launching/scripts/path.rb
index c5709d7..942d454 100644
--- a/plugins/org.eclipse.dltk.ruby.launching/scripts/path.rb
+++ b/plugins/org.eclipse.dltk.ruby.launching/scripts/path.rb
@@ -1,10 +1,10 @@
 ###############################################################################
-# Copyright (c) 2005, 2007 IBM Corporation and others.
+# Copyright (c) 2005, 2016 IBM Corporation and others.
 # All rights reserved. This program and the accompanying materials
 # are made available under the terms of the Eclipse Public License v1.0
 # which accompanies this distribution, and is available at
 # http://www.eclipse.org/legal/epl-v10.html
 #
-
 ###############################################################################
-puts $:.join(';:')
\ No newline at end of file
+print $:.join(';:')+';:'
+print Gem.path.join(';:')+';:' if defined?(Gem)
\ No newline at end of file