pybind: syntax check osd metadata

Signed-off-by: Loic Dachary <loic@dachary.org>
osd: include CPU info

It will be handy when trying to figure out CPU bound problems / benchmarks.

Signed-off-by: Loic Dachary <loic@dachary.org>
Merge pull request #889 from dachary/wip-osd-metadata

depends on #843 : CPU info + check osd metadata