ENH: io/matlab: avoid one data copy in writing zlib compressed data
ENH: io/matlab: avoid keeping data copies in memory in GenericStream
ENH: io/matlab: avoid making copies of zlib compressed data when loading files
DOC: io/matlab: update comments in code
TST: io/matlab: make structarr benchmark runnable + check with compression
MAINT: io/matlab: add a benchmark for memory usage
TST: io/matlab: mark memory benchmark runnable only on linux
TST: io/matlab: fix Py3 issue in benchmark
Merge pull request #519 from pv/mio-bigzstream

ENH: io/matlab: avoid making copies of zlib compressed data when loading files