PathIndexNG -- an efficient index for path informations

PathIndexNG is a replacement for the PathIndex. The old PathIndex is slow and
implements some functionality that is need in most use-cases.  PathIndexNG
neither supports 'or' nor 'and' operations - you query the index for one
specific path at a time. Path queries will always be matched as prefix (no
'level' parameter).

Written by Andreas Jung (andreas@andreas-jung.com)