[bugfix] Fixed critical deadlock condition in transaction manager. Please test. Port of rev 15389.
[bugfix] Fixed critical deadlock condition in transaction manager. Please test. Port of rev 15389.

svn path=/trunk/eXist/; revision=15390

dizzzz/exist,eXist-db/exist,MjAbuz/exist,shabanovd/exist,hungerburg/exist,jessealama/exist,ljo/exist,joewiz/exist,ambs/exist,hungerburg/exist,jensopetersen/exist,wshager/exist,ambs/exist,ljo/exist,patczar/exist,eXist-db/exist,eXist-db/exist,joewiz/exist,jensopetersen/exist,adamretter/exist,MjAbuz/exist,lcahlander/exist,wolfgangmm/exist,jensopetersen/exist,zwobit/exist,lcahlander/exist,joewiz/exist,lcahlander/exist,wolfgangmm/exist,patczar/exist,ambs/exist,ambs/exist,dizzzz/exist,kohsah/exist,hungerburg/exist,eXist-db/exist,jessealama/exist,MjAbuz/exist,MjAbuz/exist,joewiz/exist,ljo/exist,adamretter/exist,ljo/exist,wshager/exist,dizzzz/exist,windauer/exist,hungerburg/exist,patczar/exist,jessealama/exist,opax/exist,shabanovd/exist,RemiKoutcherawy/exist,kohsah/exist,lcahlander/exist,joewiz/exist,olvidalo/exist,adamretter/exist,MjAbuz/exist,olvidalo/exist,kohsah/exist,patczar/exist,adamretter/exist,ambs/exist,windauer/exist,jensopetersen/exist,shabanovd/exist,opax/exist,adamretter/exist,wshager/exist,opax/exist,kohsah/exist,dizzzz/exist,RemiKoutcherawy/exist,kohsah/exist,wshager/exist,shabanovd/exist,dizzzz/exist,olvidalo/exist,opax/exist,patczar/exist,zwobit/exist,kohsah/exist,wshager/exist,jessealama/exist,ljo/exist,adamretter/exist,hungerburg/exist,olvidalo/exist,opax/exist,RemiKoutcherawy/exist,zwobit/exist,shabanovd/exist,MjAbuz/exist,wolfgangmm/exist,zwobit/exist,dizzzz/exist,zwobit/exist,eXist-db/exist,wolfgangmm/exist,windauer/exist,jessealama/exist,patczar/exist,jensopetersen/exist,windauer/exist,RemiKoutcherawy/exist,wolfgangmm/exist,windauer/exist,joewiz/exist,ambs/exist,RemiKoutcherawy/exist,windauer/exist,zwobit/exist,wolfgangmm/exist,eXist-db/exist,olvidalo/exist,shabanovd/exist,ljo/exist,jessealama/exist,lcahlander/exist,lcahlander/exist,jensopetersen/exist,RemiKoutcherawy/exist,wshager/exist