VCL-1126 - allocate computer already having specified IP address for server reservations with specified IP

OS.pm: modified confirm_fixed_ip_is_available: added $computer_id argument when calling is_ip_assigned_query; added check for assigned computer having specified IP address and if so, skip ping check

utils.pm: modified is_ip_assigned_query: added 2nd (optional) argument for a computer ID; if computer ID is passed in, don't include that computer in query results

utils.php:
-modified isAvailable: added check for any mapped computers already having the requested IP address, and if so, limit mapped computers to just those and set a flag that mapped computers have been limited; at first check for no computers being available if mapped computer flag is set, use -4 return code instead of 0; if mapped computer flag set, skip removing recently reserved computers that may have failed
-modified debugIsAvailable: changed message for case 2 to say an unavailable computer has the requested IP instead of stating an overlapping server reservation has the address assigned
3 files changed