fix pango markup for python3
remove strange import proxy code

Data was basically just used as a proxy for importing
resources.default_config, which we did later in the file anyway. We can just
use a more direct way of supplying the default config.
get rid of ugly functions in utils.py

is*Like were generally ugly; they had bare excepts, required local imports for
use in xcbq.py (their only user) and weren't very clear about their logic.
Let's get rid of them in favor of something more explicit.