There was many unfixable race conditions that could only be
solved by better integrating the request:: system and
awful.rules. This has the side effect to make rules mandatory.
* This commit add a new module to avoid a (4 level) loop dependency
* It is now possible to call awful.spawn() with a table of properties
* awful.rules is used to execute the rules.
* Everything is public to allow alternative workflow modules such as
Tyrannical to use their own callback implementation.
Emmanuel Lepage Vallee
Uli Schlachter
Daniel Hahler
Julian Wollrath