Bump cabal version to 1.10
Internal reorganisation

Move "internal" definitions to MPD.Internal, for writing
tests and so on.
MPD.Internal: constrain imports
MPD.Internal: refactor readRemote
MPD.Internal: factor out connection auth
MPD.Internal: ignore exceptions on close
Add MPD exceptions

Connection and wire primitives throw MpdExceptionS on errors;
remaining IO exceptions are caught by withRemote.
Merge branch 'internal'
Merge branch 'exceptions'