. Changed DEBUG option in DEBUG for logs and MEM_DEBUG for memory purpose

. Removed *vs argument (vs is now a global variable) in each function

. Updated vlanserver.conf.sample

. snmp time out is yet implemented

. so switches are not polled the same way:
   no second init, just reasking 5 times aborting after

. Added the good #includes in order not to have to put the snmp prototypes
  in our code

. Removed a segfault in snmp when using traps

All this seems to work well.
BUT there is always the current segfault.
 I think now that it relies on double use of libsnmp
   I mean call to snmp_create_pdu inside one of our function which is itself
   called by snmp_read. Seems not to be allowed.
   I'm gonna try not to resend anything in callback.c but pushing requests
   to main loop in order to execute snmp functions outside snmp_read.