fixed issue 1695
Fix changing encoding on shared ByteList
* Keep consistent Gem version using '.' instead of '-' as delimiter.
make the layout lazy on StructByReference to allow to use self.ptr inside the layout. possible fix for #1729

Conflicts:
	spec/ffi/managed_struct_spec.rb
Merge pull request #1703 from k77ch7/GH-1695

Fix for issue #1695
Merge with jruby-1_7