modify code to suppress or fix warnings in gcc and clang (#41)

* first fix to start branch PR

* explicit conversion from sizet to int

* Array.h and DiagonalMatrix.h

* many sizet to int conversions

* removed some unused variables and added expl overrides

* removed many unused parameters

* more typing

* even more

* last of the easy changes

OndselSolver/SystemSolver.cpp

@@ -33,7 +33,7 @@ using namespace MbD;
 
 //class PosICNewtonRaphson;
 
-void SystemSolver::setSystem(Solver* sys)
+void SystemSolver::setSystem(Solver*)
 {
 	//Do not use
 	assert(false);