[MERGE] ir.cron: rollback db transaction upon job execution failure (courtesy of...

Tristan's original patch included better debugging, but the logging has been improved recently,
and moved to pythonic logging, so this part was removed during the merge.

bzr revid: odo@openerp.com-20110118211230-z1gipsfeq2tna210

diff --cc bin/addons/base/ir/ir_cron.py
index 4236caf,98275b9..94e8f7d
--- 1/bin/addons/base/ir/ir_cron.py
--- 2/bin/addons/base/ir/ir_cron.py
+++ b/bin/addons/base/ir/ir_cron.py
@@@ -93,8 -91,11 +93,9 @@@ class ir_cron(osv.osv, netsvc.Agent)
              try:
                  f(cr, uid, *args)
              except Exception, e:
+                 cr.rollback()
 -                self._logger.notifyChannel('timers', netsvc.LOG_ERROR,
 -                                           "Job call of self.pool.get('%s').%s(cr, uid, *%r) failed\n%s" %
 -                                           (model, func, args, tools.exception_to_unicode(e)))
 -                self._logger.notifyChannel('timers', netsvc.LOG_DEBUG, traceback.format_exc())
 +                self._logger.exception("Job call of self.pool.get('%s').%s(cr, uid, *%r) failed" % (model, func, args))
 +
  
      def _poolJobs(self, db_name, check=False):
          try: