Reading in packets in dwepcrack

It is possible to significantly reduce the time it takes to read in 
packets in dwepcrack.  Right now the problem is that it includes an 
O(N^2) algorithm with a high constant -- it compares every candidate 
weak IV against every previous candidate IV, using memcmp.  One way to 
fix this (easy, but somewhat memory intensive) is to create a hash 
table 2^24 entries long.  Then you need not enter the "B" loop in 
weakksacrack if the iv has been seen before.  This allows you to remove 
the memcmp (and, incidentally, the goto)