Algorithm::begin/endRun: print warning if used in serial job
To enable better migration of Algorithms to MT, detect if derived Algorithm classes implement begin/endRun methods, and print a warning message if so.
No checks should be necessary for MT code, only serial, as the MT EventLoopMgr doesn't call Algorithm::sysBegin/EndRun.
This is a temporary check until all Algorithms have been migrated, and we can remove the methods entirely.
Edited by Charles Leggett