OpenSlide 3.3.1 released

[Benjamin Gilbert]

Hi,

OpenSlide 3.3.1 has been released, parallelizing concurrent 
openslide_read_region calls, improving performance on MIRAX and 
Hamamatsu VMS, and adding experimental tile size properties.

As usual, it's at:

     http://openslide.org/download

Thanks,
--Benjamin Gilbert