Added windows support. Removed inline compilation.

 - Detecting windows during FFI bindings and using correct libraries
 - Async tests are currently segfaulting a lot, so they're commented out
 - All other tests (not marked pending) are passing
 - The need for inline compilation has been removed
   + This makes it much easier to use the library on windows, where build
     support is more difficult
   + Detecting oid_size by using read_objid and counting the width between
   bits
   + FD_SETSIZE is currently hardcoded. This needs to be fixed, but is
   working well on windows.