Remove unused function.
Remove access to invalidated callspec pointer.
Merge pull request #160 from yallop/callspec-pointer-invalidation

Remove access to invalidated callspec pointer.
Add ocamlfind package flags to cmx/cmi make rules.
Pass both '-package thread' and '-thread'.
Introduce a direct-mapping type for `bytes'.
Type printing for the bytes type.
Cstubs support for 'bytes'.
Simple test for passing 'bytes' values.
Merge pull request #148 from yallop/whitequark-bytes

Support for passing 'bytes' values directly to C
Add bytes to the META "requires" field
Tests for zero-argument callbacks.
Handle zero-argument callbacks.
Merge pull request #163 from yallop/zero-argument-callbacks

Zero argument callbacks
Finish renaming "bufferspec" to "callspec".