Fix: Many missing Pygments formatters, highlighters, and lexers now included.
Fix: Subdivide imports on a per-module basis, making them finer-grained,
       per Hartmut Goebel's suggestion.
Fix: Avoid relative import.
Docs: Tweak working to clarify the use of collect_submodules.
Add: A test for pygments.
Fix: Drop use of relative imports.
Merge pull request #111 from bjones1/pygments-fix

Pygments fix.