[Truffle] Fix iterator class for the included modules iterators.
Revert "Revert "expand path before adding it to the $CLASSPATH variable""

This reverts commit 59c9f74f81701eb77d66400994873099ccf30c72.
Revert "Revert "get the $CLASSPATH variable right and allow proper URL as well""

This reverts commit b555717929916000089e0769711d4251b9fe0e82.
not using lib/jruby.jar to test $CLASSPATH

adding lib/jruby.jar on the fly to Thread.currentThread.contextClassLoader (CCL)
where is parent has already lib/jruby.jar is not an good idea especially
if the CCL is the JRubyClassLoader looking first into itself before going to
its parent CL to load classes.

further I added test to ensure that the added $CLASSPATH entry indeed
is part of the classloader.

fixes #2276
[Truffle] Fix RubyModule.includedModules.

* Remove RubyModule.selfAndIncludedModules since it is buggy.
dead code?
Add make and C++ as development dependencies.
Fix position info for rootnode and highest block node in presence of only BEGIN nodes
Added a new test for BlockNode position info when wrapping BEGINs.
rexml patch
[Truffle] Implemented Kernel#eval with a String-coerced argument.
[Truffle] Raise the correct exception type if type cannot be coerced into String.
Add echo $HOME to travis script.
[Truffle] Make $_ thread local and use it in implicit matches.
[Truffle] Handle the case where 'to_str' returns something other than a RubyString.
[Truffle] Fixed exception message when boxed primitives are used.

We want to use the Ruby logical name, e.g., Fixnum rather than java.lang.Integer.
[Truffle] Uniform guards for type.
[Truffle] Last of the top-level language Regexp specs.