Corrected document unlocking (refs #3918)

Added call to _OFFLINEDOMAIN::setReservation() in
_OFFLINEDOMAIN::removeUserDocument().
Renamed _OFFLINEDOMAIN::insertDocument to _OFFLINEDOMAIN::domainInsertDocument (refs #3955)
Merge pull request #44 from eguaj/1.6-A3918

Corrected document unlocking and renamed conflicting method (closes #3918)(closes #3955)