Lots of printers report incorrect status via SNMP

[jerome]

I've now received sufficient crash reports about this problem to handle it in PyKota's code. I suppose the printers are at fault, but that's many of them. Here's the traceback :

ERROR:     return snmp.Handler(self, printer, skipinitialwait).retrieveInternalPageCounter()                                                                                               
ERROR:   File "/usr/local/lib/python2.6/dist-packages/pykota/accounters/snmp.py", line 255, in retrieveInternalPageCounter                                                                 
ERROR:     self.waitIdle()                                                                                                                                                                 
ERROR:   File "/usr/local/lib/python2.6/dist-packages/pykota/accounters/snmp.py", line 223, in waitIdle                                                                                    
ERROR:     self.retrieveSNMPValues()                                                                                                                                                       
ERROR:   File "/usr/local/lib/python2.6/dist-packages/pykota/accounters/snmp.py", line 288, in retrieveSNMPValues                                                                          
ERROR:     self.printerStatus = int(varBinds[1][1].prettyPrint())                                                                                                                          
ERROR: ValueError: invalid literal for int() with base 10: ''     

This problem was fixed in the latest development tree, but never backported to 1.26_fixes. In addition, there was no informational message logged when this happened. This should be fixed.

[jerome]

(In [3518]) Backported some code from latest development tree to fix #59.