Changes from 2.13.1 to 2.13.2

• Better checking for SSSE3 availability in Visual Studio. Probably fixes #546 too.
  Thanks to @t20100 (Thomas Vincent) for the PR (#586).

• Documented the globally registered filters and codecs. See:
  https://www.blosc.org/c-blosc2/reference/utility_variables.html#codes-for-filters
  https://www.blosc.org/c-blosc2/reference/utility_variables.html#compressor-codecs