Fix spelling, spacing, and unused variables (#236)

* Fix spelling, spacing, and unused variables

* Fixed typo in 3 more models

* Added open back

* Remove setBackendAndTarget functions from C++ demos, which are unused functionality.

demo.cpp

@@ -46,7 +46,8 @@ public:
     {
         this->strides = { 8, 16, 32, 64 };
         this->net = readNet(modelPath);
-        setBackendAndTarget(bId, tId);
+        this->net.setPreferableBackend(bId);
+        this->net.setPreferableTarget(tId);
         this->project = Mat::zeros(1, this->regMax + 1, CV_32F);
         for (size_t i = 0; i <= this->regMax; ++i) 
         {
@@ -57,12 +58,6 @@ public:
         this->generateAnchors();
     }
 
-    void setBackendAndTarget(Backend bId, Target tId)
-    {
-        this->net.setPreferableBackend(bId);
-        this->net.setPreferableTarget(tId);
-    }
-
     Mat preProcess(const Mat& inputImage)
     {
         Image2BlobParams paramNanodet;

demo.py

@@ -148,7 +148,7 @@ if __name__=='__main__':
         img = vis(preds, image, letterbox_scale)
 
         if args.save:
-            print('Resutls saved to result.jpg\n')
+            print('Results saved to result.jpg\n')
             cv.imwrite('result.jpg', img)
 
         if args.vis: