Name email retrieval

Retrieving
To automatically fill in the packagers name and email, we should take the following order of steps until a result is reached:


 * check if we saved it from the last time
 * check if $DEBEMAIL / $DEBFULLNAME are set
 * check gnome/kde username profile
 * if we got here, then leave it blank.

Saving

 * overwrite$DEBEMAIL / DEBFULLNAME on exit (rationale - this is a global setting and should be the same in all apps
 * No: say I want another email than for my ohter apps. If you want to change your global name / email their is a dedicated place in the Desktop environment. We could consider to ask the user wat to do, but I think this only breaks program flow... (nasam)
 * Sorry, meant the DEB* enviroment variables, not the DE ones
 * save the name/email into our own configuration