a GConf "database"
A <g-conf-engine> represents a connection to the GConf database. The
default <g-conf-engine>, returned from gconf-engine-get-default,
represents the user's normal configuration source search path.
Configuration-related utilities, such as a configuration editor tool, might wish
to access a particular configuration source directly; they can obtain a
non-default <g-conf-engine> with gconf-engine-get-for-address.
Once you have a <g-conf-engine>, you can query and manipulate
configuration values.