* doc/gramps-manual/C/mainwin.xml: fixed spelling
* src/Errors.py: Add a DatabaseError type
* src/Utils.py: detect database loops in descendants_too_old
* src/WriteGedcom.py: report error message when database loop is detected
* src/po/template.po: added new error message. May be too late for some
translations to get this message.
svn: r5149
ce31ffcb84