GlideinWMS

When making one of the following changes in frontend.xml:
- frontend_versioning='True' (default is False, first line of XML)
- work base_dir different from /var/lib/gwms-frontend/vofrontend/ (this is the default and is also in /etc/init.d/gwms-frontend script)
then the RPM installation is not working.

1. update and reconfig commands use the settings in the frontend.xml file
2. startup uses /var/lib/gwms-frontend/vofrontend/ as working directory (as set in the init file) and is not finding the files created by the update/reconfig steps

This was discovered troubleshooting Farrukh installation.
I'm adding a note to the RPM instructions.

We'll have to:
- test if the tarball installation (and its init scripts) works fine
- decide if it is enough to document this or:
- some error message in the init script should highlight the config inconsistency
- the init scripts should be flexible and follow the configuration file
- some configuration options should be disabled (at least in the RPM installation)

The current work-around:
- work base_dir has to be /var/lib/gwms-frontend/vofrontend/
- frontend_versioning has to be False (first line of XML)
These (different work dir and versioning) are configurations that make sense for tarballs when you install multiple versions. There is supposed to be a single RPM installation with files all at a well defined place so these configuration options don't play well with it.
Those 2 changes will fix the problem.

Cheers,
Marco