Clean up org-mode capture system

- improve capture templates
- remove clock-in out stuff since I don't currently use clocking,
Comment out org-contacts support

I use a contacts.org file, but no current need for org-contacts/gnus.
Maybe add it back at some point.  My current contact capture template
does not depend upon it.
Prefer horizontal window splitting by default

Add function to check if there is only one window and, if so, force
horizontal (side-by-side) split.