High: config: New configuration file format

New configuration file format, described in doc/configuration.txt

- Installed in /etc/crm/crm.conf.
- Can be overridden per-user in ~/.config/crm/crm.conf.
- Options sublevel is extended with set/get commands.
- The old commands still work (except for the color scheme commands)
- Allow configuration of individual colors.
- An old RC file is loaded if found and there is no per-user crm.conf.