TB2-history-notbenh merged

[Michael G Schwern]

I just finished fixing and merging TB2-history-notbenh branch. That was
notbenh's grand unified "fix all the History issues at once" branch. That
covers...

* Adding Test::Builder2::NoHistory
* Historical statistics gathering
* Protection against test count flooding
(ie. avoiding ok 12345678 making an array of 12345678 elements)
* Storing begin/end test stream events in History
(now everything that gets passed to Formatter gets passed to History)
* Pushing the counter out of history and into the TAP formatter

And as a consequence I had to finally get around to making a singleton for the
Formatter object, so now the default builders share one default formatter.

Which is awesome work, thank you Ben!

PS Don't anyone else try to fix everything in one branch please.

--
Reality is that which, when you stop believing in it, doesn't go away.
-- Phillip K. Dick