Add missing basic examples

C++:
 - [Up] linear_programming
 - [Up] integer_programming
 - constraint_programming_CP / rabbits_pheasants_cp
 - knapsack
 - max_flow / min_cost_flow
 - tsp / vrp
note: previous "fuzzy" tsp has been renamed random_tsp.

.Net:
 - vrp

examples/java/Vrp.java

@@ -12,7 +12,6 @@
 // limitations under the License.
 import java.io.*;
 import static java.lang.Math.abs;
-//import java.util.*;
 
 import com.google.ortools.constraintsolver.RoutingModel;
 import com.google.ortools.constraintsolver.NodeEvaluator2;