Watchdbg, grepdbg args change, fix pc92c for rbn

As Changes says:
1, Change interface to watchdbg & grepdbg slightly so that multiple search
   regexes are ANDed rather than ORed together. ORing is easily achieved
   already by the usual regex pattern 'PATT..|PATT..|..' whereas ANDing could
   not be done as easily without resorting lots of 'PATT.*PATH' things which
   would not necessarily get what was wanted.
2. Make sure that the pc92 C record only contains nodes and users and not
   other extranoeus things like skimmers...