create ~/.pulp with correct perms, and warn when it has wrong perms

https://bugzilla.redhat.com/show_bug.cgi?id=1163451
I started down that road, but this was the complication: I need to handle both of these scenarios the same way:

- e is an OSError but e.errno != errno.ENOENT
- e is not an OSError

In both cases, the ``else`` block below needs to run. Adding another ``except`` statement made the flow more complex, less readable, and probably would have required duplication of code (just 2 lines though).