Move to talloc

The edited arrays should really be statically allocated for a REQUEST,
and re-used.  Re-allocing memory is bad.
Rules for clang analyzer

do "make scan" for a LONG build, with lots of scanning,
and (for now) a number of errors.
Use clang analyzer macro to tell it about asserts
Clean rules for scan
Be more careful about initialization in a loop
One more minor assert
Realm struct to talloc
Don't need to assign result of talloc_steal