[FIX]tools, translate: more tolerant code, if the model does not exist anymore (impossible to syncrhonize translation terms if there are ir_model_fields with non-existing models)
[FIX] orm: browse() do not prefetch deprecated fields
[MERGE] forward port of branch saas-2 up to revid 4989 chs@openerp.com-20131127152537-wkof87ut5cdud6z6