Allow for local (per-machine) configuration not in repository.

This is for stuff that are truly local to the machine.
Never kill org buffers. It is bad for time tracking. :)
SystemWindowText is not defined in debian/ubuntu. Just say "black"
A few global settings:

- Enable cua-selection-mode globally. This is mainly for rectangle selection.
- Enable dired find-alternate-file.
Add a more schemas and fix how maven schema is used:

- new schemas: ant, spring beans, and struts
- detect maven schema based on namespace usage, not file name.