- Indicate how to increase coverage?
- Collect data for path coverage.
- Tests.
- Documentation.
- Profiling and speedups.
- BEGIN and END blocks.
    Code in modules without subs.  Requires callbacks from perl?
- Move away from Data::Dumper.  To?
- Work with memoize.
- Fix up Devel::Cover::Op
- See if the XS code leaks, and fix it if it does.
- Specify where html output goes.
- Different criteria for different runs.
- Improve textual output.
- Add platform and version info to DB.
- Refactor output routines to use common template data.
- Add popups to html output to specify x/y = z% (or some other way)
- Look at time coverage again - collecting for too many ops?
- MD5 file and check it hasn't changed.
- Add -blib option defaulting on if blib directory is present.
- Make path to DB absolute based on cwd.
- Merge data from dynamically created subs.
- Separate output for pod coverage, like subroutine coverage.
