osutil: selfpath for windows, and make it public.

Change-Id: Ic3e8de6e75651921cb29e3b5e91cdb9f5159896a
Merge "osutil: selfpath for windows, and make it public."
GCE: use host's /tmp dir instead of inside container.

Change-Id: I2a52249148541c97dfdd84bac57a1605e0366471
Merge branch 'master' of https://camlistore.googlesource.com/camlistore