hi_pr version 3.5, 6/29/04

hi_pr is a derivative of the h_prf code of Cherkassky and Goldberg.
The code has been rewritten to make it more maintainable and stable.

Algorithmic changes include array representation of adjacency lists (compared
to the linked list representation in h_prf) and initialization (done by 
saturating all out-of-source arcs rather then placing a large excess at 
the source); also by default, global update is not performed immediately
after initialization. Old initialization is supported via a compiler option.

Version 3.2 differs from 3.1 by a slightly different strategy for measuring
work to decide when to envoke the next global update. Version 3.3 fixes a
bug in the second (flow computation) stage, implements excessType better,
and adds a CHECK_SOLUTION compiler option.Version 3.4 adds cType 
(capacity type) and the ability to reinitialize computation using init()
function. Version 3.5 adds wave-type initialization, which is better on
some problem families (and worse on others). Version 3.5 also uses less memory.
