Log Message:
Update ruby-ffi to 1.9.10.

1.9.10
* Simplify clean list and add libtest build files.
* methodHandleParamTypes needs to refer to valid memory after rbffi_MethodHandle_Init
* tweak travis to allow failure in 2.2 on osx
* allow failure on osx 2.2 and head builds
* CLEAN tweak [ci skip]

1.9.9
* workaround bundler problem
* fix struct specs on 1.8 sets them to pending rather than checking for a raise \ 
but...
* better clean/clobber config
* Simplify cross build tasks and add rake-compiler-dock for building Windows \ 
binary gems.
* Added Platform.solaris? singleton method.
* fix library load... forever
* better native_type
* enable and fix warnings in specs.
* add compiler and platform based tests
* Fix compatibility with newer libffi on Windows/MSVC
* Handle better RUBY_VERSION.