[IMP] code style improvements
[IMP] code style improvements

* Remove unused variables
* Simplify dict.get call in conditionals (default is None)
* Simplify dict.update calls (use kwargs)
* Merge dict.copy() with dict.update() as dict()
* Use isinstance instead of type() equality tests
* Simplify deeply nested code: merge conditionals and remove useless
  conditional, use dict.iteritems()
* Log traceback in exception handler logging

splbio/openobject-server,MarkusTeufelberger/openobject-server,MarkusTeufelberger/openobject-server,ovnicraft/openerp-server,gisce/openobject-server,gisce/openobject-server,gisce/openobject-server,MarkusTeufelberger/openobject-server,splbio/openobject-server,ovnicraft/openerp-server,splbio/openobject-server