[PATCH] Add timestamps to "maint time" output

[Tom Tromey]

>>>>> "Tom" == Tom Tromey <tromey@adacore.com> writes:

Tom> Currently "maint time" will print the amount of time a command took.
Tom> Sometimes, though, it's useful to have a timestamp as well -- for
Tom> example if one is correlating a gdb log with some other log.

Tom> This patch adds a timestamp to the start and end of each command when
Tom> this setting is in effect.

Tom> This also removes a "//" comment and changes scoped_command_stats to
Tom> use DISABLE_COPY_AND_ASSIGN; two minor things I noticed while working
Tom> on the patch.

I'm checking this in now.

Tom