Added support for trimming the contents of parsed Xml graph

include/osgDB/XmlParser

@@ -33,6 +33,8 @@ inline XmlNode* readXmlFile(const std::string& filename)
 /** read an Xml from from an istream.*/
 extern OSGDB_EXPORT XmlNode* readXmlStream(std::istream& fin);
 
+extern OSGDB_EXPORT std::string trimEnclosingSpaces(const std::string& str);
+
 /** XmlNode class for very basic reading and writing of xml files.*/
 class OSGDB_EXPORT XmlNode : public osg::Referenced
 {
@@ -60,6 +62,8 @@ class OSGDB_EXPORT XmlNode : public osg::Referenced
         Properties      properties;
         Children        children;
 
+        std::string getTrimmedContents() const { return trimEnclosingSpaces(contents); }
+
     public:
 
         class OSGDB_EXPORT Input