Three otherwise unrelated framework changes needed for the new mixing feature for premixed pileup stored as raw data..

1) Add a new function, setRunAndLumiNumber, to class EventPrincipal.

2) Remove an unused data member, procPset_, from class WorkerParams.

3) The current class "Schedule" does (at least) three different things:
a) Manage the schedule (e.g. paths, end paths, etc.)
b) Manage unscheduled (i.e. on demand) execution of modules
c) Manage the workers, which in turn manage the modules.
Functions b) and c) are removed from "Schedule" and moved to a new class, "WorkerManager".

This tagset has been fully tested. All relvals pass.

--- Tagset history ---
2013-06-13 20:31:50 - Queued by wmtan.
Improve exception message for unscheduled circular dependences

--- Tagset history ---
2013-06-19 18:03:39 - Queued by wdd.
Merge pull request #36 from ktf/tagset-133254

Three otherwise unrelated framework changes needed for the new mixing fe...
Merge pull request #35 from ktf/tagset-133410

Improve exception message for unscheduled circular dependences