Fix min/ max calculation by removing all soft constraints before doing so. Smaller fixes.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40297 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/libs/linprog/LinearSpec.h

@@ -148,6 +148,7 @@ private:
 									double penaltyNeg, double penaltyPos);
 
 			VariableList		fVariables;
+			VariableList		fUsedVariables;
 			ConstraintList		fConstraints;
 			ResultType			fResult;
 			bigtime_t 			fSolvingTime;

headers/libs/linprog/Variable.h

@@ -58,6 +58,9 @@ public:
 protected:
 								Variable(LinearSpec* ls);
 
+			//! returns the ref count
+			int32				AddReference();
+			int32				RemoveReference();
 private:
 			LinearSpec*			fLS;
 
@@ -68,6 +71,7 @@ private:
 
 			bool				fIsValid;
 
+			int32				fReferenceCount;
 public:
 	friend class		LinearSpec;
 };