Different conditions for printing taskqueue statistics for parallel gc, parNew and G1

When enabling task queue statistics (define TASKQUEUE_STATS in taskqueue.hpp) parallel gc and g1 require different flags enabled to print the statistics.

In particular, for Parallel gc and ParNew the condition PrintGCDetails && ParallelGCVerbose is used, while in g1 only ParallelGCVerbose is needed.

I would prefer that all use ParallelGCVerbose as this flag is used only for that purpose anyway.

Also, parallel gc always prints into "tty", while the others use "gclog_or_tty". Please change default to gclog_or_tty like the others.

G1 also prints a "totals" row that sums up the values, the others do not

There does not seem to be a reason for these differences.

ILW: L (needs some additional flags defined), H (always if TASKQUEUE_STATS are compiled in), H (no workaround) -> P5 anyway because it needs changes to the source code