Adding MANIFEST.in and fixing .gitreview

Bit-rot from no development going on has led to some problems. The
.gitrview file points at the old named repo. MANIFEST.in is needed to
make sure we have README.md to satisfy setup.cfg using it for the long
description.

Change-Id: I9ba5b2c1eda349b26d24833ebd5cbd5244584311
Fix relative imports and namespace issues.

os_apply_config.os_apply_config caused confusing import problems.
Renaming it to os_apply_config.apply_config solves this. Now we can be
explicit about all imports.

Change-Id: I7b0c5fe18e27e16b5db73e30480de865a332b8d2