Fix copy/paste errors in API docstrings

Fix some inappropriate docstring, like:

1. "Gets detailed information for a stack" as the docstring for show() in
   events.py
2. "Lists summary information for all resources" as the docstring for
   index() in events.py
3. "Gets detailed information for a stack" as the docstring for show() in
   resources.py
4. "Gets detailed information for a stack " as the docstring for
   metadata() in resources.py

Change-Id: I38fc6a18224d1537bf6981ba60bffc31768b7443
Closes-Bug: #1261615
Merge "Fix copy/paste errors in API docstrings"