Standardize the Moo import block, move quote_sub/qsub into ::_Util

This way we will have less boilerplate in subsequent commits where we
will use quote_sub standalone

Add yet another test to make absolutely sure quote_sub won't leak any of the
strictures insanity
Reformat add_relationship_accessor for future edit

No functional changes, read diff under -w
Replace many proxy closure-based methods with static qsubs

Not only does this buy a quantum of performance, but it greatly enhances
readability of these methods on deparse

Deliberately not converting the ManyToMany helper - this code needs a
thorough regut :(