Add MIP starts and README of Irv Lustig submission

Irv_Lustig/models/README.txt

+The 3 problems enclosed represent a set of sequential solves using 
+hierarchical optimization, via 3 objectives.
+
+The problem seqsolve.1.mps is the first problem to solve.  The objective 
+is called "shortage".  The best known solution has an objective of 4288.
+
+The problem seqsolve.2.short4288.mps is the second problem to solve. 
+The objective is called "excess". It has a constraint called shortageBound 
+that adds 0.25 to the objective of the first problem, so that the 
+new objective is minimized without making the first objective worse. 
+In the RHS section of the MPS file is the line:
+    RHS1      shortageBound  4.28825e+03
+
+If a better objective value than 4288 is found for seqsolve.1.mps, 
+then the above line should be changed.
+
+The best known solution for the second problem (given the objective 
+bound derived from the first problem) is 384.
+
+The problem seqsolve.3.short4288.excess384.mps is the third problem 
+to solve. The objective is called "preference". It has 2 constraints, 
+shortageBound and excessBound that each add 0.25 to the objectives 
+of the first and second problem, respectively, so that the new 
+objective is minimized without making either of the first two 
+objectives worse. In the RHS section of the MPS file are the lines:
+    RHS1      shortageBound  4.28825e+03
+    RHS1      excessBound  3.8425e+02
+
+If a better objective value is obtained for the first or second 
+problems, then these values should be modified.
+
+Note that the last feasible solution for the first problem should be 
+used as a MIP start for the second problem.  Similarly, the last 
+known feasible solution for the second problem should be used as a 
+MIP start for the third problem.  For convenience, the Gurobi MST 
+files first.mst and second.mst are supplied, representing the MIP 
+start to use for seqsolve.2.short4288.mps and 
+seqsolve.3.short4288.excess384.mps, respectively.
+
+Each of the problems were solved with Gurobi 7.0.0 on a Intel Core 
+i7-4800MQ CPU @ 2.70GHz, with 4 physical cores, and a total of 8 
+logical processors.  The solver was stopped after 10 hours of 
+computation for each run.  Here is a summary of the results:
+
+Problem                         Objective          Bound              Gap
+seqsolve.1                      4.288000000000e+03 4.275000000000e+03 0.3032%
+seqsolve.2.short4288            3.840000000000e+02 1.771829204207e+01 95.3859%
+seqsolve.3.short4288.excess384 -3.061900000000e+04 4.245900000000e+04 38.6688%
+
+The gurobi.log file for the 3 solves is also included.
+
+Submitted by Irv Lustig, Princeton Consultants, 11/22/16