Remove using std::XXX from headers

This is a bad practice to have using in headers because it pollutes the
namespace of any user of that header.
diff --git a/parameter/XmlFileIncluderElement.cpp b/parameter/XmlFileIncluderElement.cpp
index 2e97bdb..e9b95cd 100644
--- a/parameter/XmlFileIncluderElement.cpp
+++ b/parameter/XmlFileIncluderElement.cpp
@@ -36,8 +36,8 @@
 #include <assert.h>
 
 #define base CKindElement
-CXmlFileIncluderElement::CXmlFileIncluderElement(const string& strName,
-                                                 const string& strKind,
+CXmlFileIncluderElement::CXmlFileIncluderElement(const std::string& strName,
+                                                 const std::string& strKind,
                                                  bool bValidateWithSchemas) : base(strName,
                                                                                    strKind)
 {
@@ -51,7 +51,7 @@
     CXmlElementSerializingContext& elementSerializingContext = static_cast<CXmlElementSerializingContext&>(serializingContext);
 
     // Parse included document
-    string strPath = xmlElement.getAttributeString("Path");
+    std::string strPath = xmlElement.getAttributeString("Path");
 
     // Relative path?
     if (strPath[0] != '/') {
@@ -60,13 +60,13 @@
     }
 
     // Instantiate parser
-    string strIncludedElementType = getIncludedElementType();
+    std::string strIncludedElementType = getIncludedElementType();
     {
         // Open a log section titled with loading file path
         CAutoLog autolog(this, "Loading " + strPath);
 
         // Use a doc source that load data from a file
-        string strPathToXsdFile = elementSerializingContext.getXmlSchemaPathFolder() + "/" +
+        std::string strPathToXsdFile = elementSerializingContext.getXmlSchemaPathFolder() + "/" +
                                strIncludedElementType + ".xsd";
 
         CXmlFileDocSource fileDocSource(strPath,
@@ -116,9 +116,9 @@
 }
 
 // Element type
-string CXmlFileIncluderElement::getIncludedElementType() const
+std::string CXmlFileIncluderElement::getIncludedElementType() const
 {
-    string strKind = getKind();
+    std::string strKind = getKind();
 
     int iPosToRemoveFrom = strKind.rfind("Include", -1);