Several packages must precede `cleveref` if loaded at all.

Most of these come from `\@ifpackageloaded` checks in `cleveref.sty` that
add special support if the other package is already loaded.  One is also
mentioned explicitly in the `cleveref` documentation.
Enforce delicate ordering among `cleveref`, `hyperref`, and `varioref`.

The `cleveref` documentation explicitly states the order in which these
must be loaded if all three are used.  Other rules already put `hyperref`
and `varioref`  before `cleveref`.  This adds the final necessary
constraint to enforce the correct total ordering among all three packages.
Whitespace-only changes to keep similar syntactic elements aligned.
Combine several similar `before` rules into one equivalent `after` rule.
Shorten `because` justification by paraphrasing instead of quoting.
Group rules by origin, and add attribution thereto.
Whitespace-only changes to align only within each group of rules, rather than globally.
Merge pull request #2 from liblit/cleveref

Ordering rules for `cleveref` and various other packages