tests: add a substitution pattern for HTTP error log dates This will make tests with error log content less of a nuisance. I didn't roll it into to $LOGDATE$ because the regex got long and line wrapped. It didn't seem worth the obscurity.

wireproto: convert python literal to object without using unsafe eval() Follows up cc5a040fe150. At this point, I don't think we need a real eval(). If we want to support a set literal, maybe we can vendor ast.literal_eval(), which is relatively simple function.

tests: quote variable passed to shell test command