add buffer_spec for FFI and fix FFI::Buffer so the tests pass.
add MRI ffi specs
last failing currently
this *should* work
After uncommenting these lines, I was able to run buffer_spec.rb to completion.
maybe I was somehow picking up my jruby-1.7.10 install then.
fixup! this *should* work
Merged by hand to jruby-1_7 and I'll merge to master now.