- added initialze and finalize methods to workloads, which were the only
major extension types that did not have them
- Semanatics for initialize/finalize for *all* Extensions are changed so
that now they will always run at most once per run. They will not be
executed twice even if invoke via istances of different subclasses (if
those subclasses defined their own verions, then their versions will
be invoked once each, but the base version will only get invoked
once).
- add IterationResult-level classifiers that get merged into every
added metric (saves having to pass the same classifiers to each
metric added).
- Added a global alias to csv result processor's use_all_classifiers
attribute.
- Adding "classifiers" field to Metric objects. This is a dict mapping
classifier names (arbitrary strings) to corresponding values for that
specific metrics. This is to allow extensions to add
extension-specific annotations to metric that could be handled in a
generic way (e.g. by result processors).
- Updating telemetry workload to add classifiers for the url and internal
iteration (or "time") for a particular result.
- Updating csv result processor with the option to use classifiers to
add columns to results.csv (either using all classifiers found, or
only for the specific ones listed).
