Extend `ETC_DIRS' functionality; improve `get_info_for_client'

The order for the ETC_DIRS has been changed, and `get_info_for_client'
breaks properly. The first "ETC_DIR" has the highest priority. If
several configurations exists, then the one in the home directory (or,
if none is there, the one in /usr/local) will take precedence.

Modified `get_info_for_client' to add variable `WANTED_CLIENT' for
clarity and coherence. Also removed `VM_TYPE' from this function
because sourcing the .conf file will set `VM_TYPE'.