Create tests for multiple server creation

This tests nova multiple servers creation using min_count and max_count
instance counters and return_reservation_id parameter.

Cause of the new tests this also add min_count and max_count to xml server
client and return_reservation_id to both clients.

Depends on changes:
    Ifaa9910e13614554d1769e71e8eba9587ec5a13b
    I3ca0129086ff1df3a8faa2b3b8bd959c9b74103c
Both on Nova.
Partially implements bp missing-tempest-tests

Change-Id: I4195b26d88632c2e679b7a6e5bd8cf9443d42553
make stack traces tool find individual traces

previously the tool just reprinted out TRACE and ERROR log lines.
Now make it actually collect up TRACE and ERROR into individual
events which will make it easier to cross reference to tempest
tests.

built additional features around stack trace tooling, making it
simpler to find unique events.

Change-Id: Id1fed3343e79e75da3145b5a9c19820b65a0d548
Merge "Create tests for multiple server creation"
Merge "make stack traces tool find individual traces"