_common.py import issue due to conflict with other package.

[inferno-chromium]

_common.py conflict with Google's grpc's _common.py when both of these packages are installed in a custom directory.
this causes an import error, is it possible to rename _common.py to something else to avoid conflicts. otherwise we have to install psutil system wide, which we want to avoid.

ImportError: cannot import name _common
at (/b/clusterfuzz/src/third_party/psutil/init.py:41)

[inferno-chromium]

looks like other people hit this too, e.g. https://community.hortonworks.com/questions/77111/from-psutil-import-common-importerror-cannot-impor.html

[inferno-chromium]

or if we can remove https://github.com/giampaolo/psutil/blob/master/psutil/__init__.py#L40

[giampaolo]

Please paste the full traceback

[inferno-chromium]

I will see if i can create a reduced repro, otherwise stack is just internal code frames.