Allow program to try vertices in some permutation

Each spot in the Rook graph can be given its own order in which to try
vertices. The default is to just try them in order. Use '-p perm.txt' to load
arbitrary permutations, where perm.txt is an ASCII file containing k*k lines
where each line consists of k*k integers separated by spaces. The i'th line
contains the permutation for spot i. This is compatible with forced allocations
stil.
Add test allocations only mode

Passing -t causes program to enter this mode. It only tests whether forced
allocations (from the command line) are good or not, then returns 0 or -1
respectively. Does not do any iteration.
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