Remove extraneous vim configuration comments

Remove vim setting, Remove line containing:
comment - # vim: tabstop=4 shiftwidth=4 softtabstop=4

at the top of source code files, except for files in
openstack/common.

Change-Id: I5e2aad6dca8407890fc3c2afbda541bd4f124ea8
Closes-Bug: #1229324
Merge "Remove extraneous vim configuration comments"