Release 1.11.2

Enabled use as a CMake subproject, exporting shared & static library targets for super-projects to use. See PRs #178, #179 and #180. Thanks to Kevin Murray.

Also, internal codecs have been updated. LZ4 and LZ4HC codecs to 1.7.5 and Zstd to 1.1.2.

For more info, please see the release notes in:

https://github.com/Blosc/c-blosc/blob/master/RELEASE_NOTES.rst