Module#ancestors now includes singletons themselves

Since Ruby 2.1, calling #ancestors on a singleton class should now
include the class itself in the chain.

Since BasicObject is at the very base of the ancestors, we also need to
change the meta class of Object so that BasicObject's singleton class
correctly get included in the chain.
Add PowerPC64 little endian support in FFI

Adds support for the ppc64le architecture in JRuby FFI.
remove useless initial load path entries of the ScriptingContainer
remove obsolete yecht dependency from jruby.jar
Re-add important line? :)
Fix RubyStruct to set the proper eval-type for new struct bodies.

* Added new unit tests for JRuby (perhaps this should go into
  rubyspec as well).
Minor cleanup (dead comment, dead method args, excess whitespace)
Move Truffle-mode tests to the entry of eval methods in IR interpreter
[Truffle] Do not try to know the caller class if we ignore the visibility.

* Ideally visbility checking and lookup should be separated.
Remove automated generated files (by mvn eclipse:eclipse) from the repository.
Remove all old Eclipse files, we'll start from scratch.
Some .gitignore cleanup
Sort the .gitignore file
Ignore Maven generated Eclipse files.
Add a couple settings files for Truffle annotation processing in Eclipse.
Have a try at keeping all Eclipse settings files since they seem to contain no path.
Eclipse: remove trailing whitespace on save.
Update some Eclipse settings.
Eclipse: have a try with the .classpath checked in repository.
Eclipse: check-in .project as well so there is minimal requirement to import the project.