Kill off all of the old osid handling that nfree did. When a node is
released, all of def_boot_osid,temp_boot_osid,next_boot_osid is cleared. bootinfo currently uses the nodes free/alloc status to determine if the node gets PXEWAIT, but will eventually switch to looking at the osids; A node with no osids set (as will be when free) will go into PXEWAIT. This will allow os_load of free nodes! Change temporary locked pid/eid to a real pid/eid (emulab-ops/nfree-locked) to avoid transient problems in tmcd, where isalive would cause tmcd to core dump cause the reserved table had a nonexistent pid/eid setting.