Changed a few method signatures to make them easier to wrap

openmmapi/include/openmm/OpenMMContext.h

@@ -134,14 +134,14 @@ public:
      * 
      * @param name the name of the parameter to get
      */
-    double getParameter(std::string name);
+    double getParameter(const std::string& name);
     /**
      * Set the value of an adjustable parameter defined by a Force object in the System.
      * 
      * @param name  the name of the parameter to set
      * @param value the value of the parameter
      */
-    void setParameter(std::string name, double value);
+    void setParameter(const std::string& name, double value);
     /**
      * When an OpenMMContext is created, it may cache information about the System being simulated
      * and the Force objects contained in it.  This means that, if the System or Forces are then

openmmapi/include/openmm/OpenMMException.h

@@ -43,7 +43,7 @@ namespace OpenMM {
 
 class OpenMMException : public std::exception {
 public:
-    OpenMMException(std::string message) : message(message) {
+    OpenMMException(const std::string& message) : message(message) {
     }
     ~OpenMMException() throw() {
     }

openmmapi/src/OpenMMContext.cpp

@@ -108,11 +108,11 @@ void OpenMMContext::setVelocities(const vector<Vec3>& velocities) {
     impl->getVelocities().loadFromArray(&velocities[0]);
 }
 
-double OpenMMContext::getParameter(string name) {
+double OpenMMContext::getParameter(const string& name) {
     return impl->getParameter(name);
 }
 
-void OpenMMContext::setParameter(string name, double value) {
+void OpenMMContext::setParameter(const string& name, double value) {
     impl->setParameter(name, value);
 }