Expand the overload test to include strong consistency

Change the overload test to exercise the strongly consistent code
paths in addition to the eventually consistent paths during overload
conditions.
Add pbc/2 function to the rt module to allow custom options to be specified
Increase the test code coverage and make the coverage checking more
robust to failures.
add a intercept/server accounting of get_fsm processes.
removed sleep
initial commit
add timeouts to calls instead of from .riak_test.config
More robustification against races between overloading the vnodes and the list_keys attempt for the coverage testing.

Conflicts:
	tests/overload.erl
Merge branch 'feature/sc-overload-testing'