rsyslog work log 32

Yesterday's rsyslog work log: 2008-02-25 - implemented data type conversion - released 3.11.5 - implemented majority of comparison operations - added some temporary testing aids to conf.c, so that we can debug expression support as it is implemented - fixed a couple of bugs in expression system - added more operations to virtual machine - now works well with constants - added PUSHMSGVAR operation to vm - included expression support in filter module (and it works ;)) - added sysvar class - added PUSHSYSVAR operation to vm - added string concatenation operator & to RainerScript - fixed segfault when pure string values were tried to be added