Made scoped_lock not CopyConstructible.

scoped_lock was CopyConstructible because synchronized macro had required copy.
Due to C++03 spec, compiling source using synchronized macro with clang generates a warning.
See: http://clang.llvm.org/docs/UsersManual.html#cmdoption-Wbind-to-temporary-copy
Merge pull request #140 from pepshiso/scoped_lock-copyconstructible

Made scoped_lock not CopyConstructible.