Better HTML page titles by normalizing path.
PEP8
Always display a filename in the title.

This includes the implicit filename so you can quickly
glance at the tab's title to know which file it is.
Handle file not found errors for directories.
Fix all references to settings_local.py.

This is leftover from e512f18a7f957c54e3e2729104ce1d1e7ce23da4.