Delete unused stat counters

Summary: All of these are unused. I suspect some of them were originally meant to
count something that we still care about (e.g. tracelet guard
executions?) but the callsites have bitrotted away.

I think we'll need automated testing if we care about a particular stat
enough to keep it. I'd like to check this diff in as-is, but it's also
partially a forcing function to get people to reinstate stat counters
that they actually care about.

Reviewed By: @edwinsmith

Differential Revision: D1515024
Get one std::vector ini bound

Summary: Let's get one collection-based ini setting bound. Choosing a `std::vector<std::string>`
based setting, `AllowedExecCmds`. If this works, then other `std::vector<std::string>`
settings should follow suit nicely.

Reviewed By: @ptarjan

Differential Revision: D1510936
Fix stack corruption in ezc_set_error_reporting() in ezc_test.cpp

Summary: Found a stack corruption bug while testing with ASAN. Fixed it.

Reviewed By: @markw65

Differential Revision: D1516723
Fix inner class specialization on Box

Summary: Drop inner class specialization on Box if the class
does not have AttrNoOverride.

Reviewed By: @alexmalyshev

Differential Revision: D1507916