Remove all using directives for STL namespace and members

Made all STL usages explicit to be able automatically find all usages of
particular class or function.

modules/legacy/src/features2d.cpp

@@ -69,7 +69,7 @@ cvExtractSURF( const CvArr* _img, const CvArr* _mask,
     Mat img = cvarrToMat(_img), mask;
     if(_mask)
         mask = cvarrToMat(_mask);
-    vector<KeyPoint> kpt;
+    std::vector<KeyPoint> kpt;
     Mat descr;
 
     Ptr<Feature2D> surf = Algorithm::create<Feature2D>("Feature2D.SURF");
@@ -111,7 +111,7 @@ cvGetStarKeypoints( const CvArr* _img, CvMemStorage* storage,
                                               params.lineThresholdProjected,
                                               params.lineThresholdBinarized,
                                               params.suppressNonmaxSize);
-    vector<KeyPoint> kpts;
+    std::vector<KeyPoint> kpts;
     star->detect(cvarrToMat(_img), kpts, Mat());
 
     CvSeq* seq = cvCreateSeq(0, sizeof(CvSeq), sizeof(CvStarKeypoint), storage);