Normalize path for finding api_samples dir

When nova/tests/integrated and doc/api_samples are installed
in different subtrees and are only combined via symlinks,
running test_api_sample fails due to traversing into the
wrong tree. Use path normalization to avoid this problem.

Fixes: LP Bug #1186775

Change-Id: Ibe9e2442dc9bf3ba7bcb429cbac124dcaeea2cef
Handle security group quota exceeded gracefully

Handle the security group quota exceeded more gracefully so a
traceback is not generated in the log files when this error
occurs. This does not change the API as the HTTP status code
returned remains the same.

Fixes bug 1182859

Change-Id: Id3ac513048751759f01b328482b4f02e26ff66ee
Merge "Normalize path for finding api_samples dir"
Merge "Handle security group quota exceeded gracefully"