It is now possible to add a list of theme configurations in the
"default" section called "cycle". These configuration items will be
cycled through module by module. to create "alternate style" effects.
This is *only* possible in the "default" configuration part, but any
module-specific configurations still take precedence.
Also, removed the capability of per-widget themes. That simply
complicates things and probably doesn't really bring any benefits.
Add - again a very simplistic - method for themeing the output.
Essentially, the plan is to have JSON-formatted configuration files in
bumblebee/themes/ and have a separate class for querying the config
whenever the output needs to know about semantic formatting/coloring.
Note that the theme object is stored on a per-module basis. Right now,
that doesn't have any effect (except looking particularly wasteful), but
the idea is to be able to have different themes for different modules in
the future.
