Added support for bool in ArgumentParser::Parameter.

Added support for using Input::read(...) methods using ArgumentParser::Paramter
to adapter to multiple paramter types.

include/osg/ArgumentParser

@@ -33,6 +33,7 @@ class OSG_EXPORT ArgumentParser
         public:
             enum ParameterType
             {
+                BOOL_PARAMETER,
                 FLOAT_PARAMETER,
                 DOUBLE_PARAMETER,
                 INT_PARAMETER,
@@ -42,6 +43,7 @@ class OSG_EXPORT ArgumentParser
         
             union ValueUnion
             {
+                bool*           _bool;
                 float*          _float;
                 double*         _double;
                 int*            _int;
@@ -49,6 +51,8 @@ class OSG_EXPORT ArgumentParser
                 std::string*    _string;
             };
 
+            Parameter(bool& value) { _type = BOOL_PARAMETER; _value._bool = &value; }
+
             Parameter(float& value) { _type = FLOAT_PARAMETER; _value._float = &value; }
                 
             Parameter(double& value) { _type = DOUBLE_PARAMETER; _value._double = &value; }
@@ -83,6 +87,9 @@ class OSG_EXPORT ArgumentParser
         /** Return true if specified parameter is a number. */
         static bool isNumber(const char* str);
 
+        /** Return true if specified parameter is a bool. */
+        static bool isBool(const char* str);
+
     public:
 
         ArgumentParser(int* argc,char **argv);