- renovated mib and added descriptions and comments

- renovated mib and added descriptions and comments
- added hit and byte counters to client_db , for cacheClientTable
- cacheClientTable, netdbTable, cachePeerTable, cacheConnTable and
  fqdnCacheTable are now indexed by ip address. hash_lookup was enhanced
  to allow for subsequent hash_next's similar to hash_first-hash_next,
  to speed up getnext's in tables which refer to hash-table structures.
- added generic (well, sorf of) table indexing functionality
- added makefile dependencies for snmplib and cache_snmp.h
- WaisHost, WaisPort, Timeouts removed
- FdTable split into FdTable and ConnTable. FdTable simplified
- PeerTable and PeerStat merged and put into new cacheMesh group
- cacheClientTable added for client statistics and accounting (cacheMesh 2)
- cacheSec and cacheAccounting groups removed
- fixed acl bug when communities not defined
- acl config now survives bad configuration (public is defined "implicitly")