- Pass tagtype from v2 directory to libtiff encoder, instead of
autodetecting type.
- Use explicit types. E.g. uint32_t for TIFF_LONG to fix issues on
platforms with 64bit longs.
- Add support for multiple values (arrays). Requires type in v2
directory and values must be passed as a tuple.
- Add support for signed types (e.g. TIFFTypes.TIFF_SIGNED_SHORT).

Uses JPEGQUALITY pseudo-tag from libtiff.

Also changes the way tags are passed to PyImaging_LibTiffEncoderNew from
dict to list to ensure that COMPRESSION tag is added before JPEGQUALITY.
This is required as the COMPRESSION tag registers the JPEGQUALITY
pseudo-tag.