clarify object's IP allocations rendering

'aac' global, '.aac' css class renamed to 'aac-right'
'aac2' global renamed to 'aac-left', corresponding css class created
getRenderedAlloc: fix missing <td> tag in 'td_routed_by' field
renderObject: align th labels by left side
renderFile: remove unused global declarations
new library call makeIPAllocLink()

getRenderedAlloc: use getRenderedAlloc
renderIPv4NetworkAddresses: idem
renderIPv6NetworkAddresses: idem
renderIPAddress: idem
renderIPAddressAllocations: idem
new 'point2point' IP alloc type

genericAssertion: new array item 'point2point'
markupIPAddrList: idem
getPtPNeighbors: call to search for ptp peers in the network's addrlist
getRenderedAlloc: display peers near the ptp-typed allocations
fix ip4_parse, ip6_parse

If inet_pton() supports IPv6, it is possible that ip4_parse('::')
will return 16-byte binary address.