Support %LA (AND), %LO (OR) and %LQ (comma) conversions for qsprintf() to improve safety
I believe we can cover all these cases (or, at least, almost all these cases) with conversions for imploding on AND, OR, or comma. This will ultimately let us make %Q safer.
Test Plan: Played around with these in a toy qsprintf() script; upcoming changes will convert Phabricator callsites more aggressively.
Reviewed By: amckinley
Differential Revision: https://secure.phabricator.com/D19783