Merge pull request #106 from Yarikx/remove_floatmath

remove useage of FloatMath class, use Math instead

Author: davemorrissey

library/src/com/davemorrissey/labs/subscaleview/SubsamplingScaleImageView.java

@@ -38,7 +38,6 @@
 import android.support.annotation.NonNull;
 import android.util.AttributeSet;
 import android.util.DisplayMetrics;
-import android.util.FloatMath;
 import android.util.Log;
 import android.util.TypedValue;
 import android.view.GestureDetector;
@@ -1760,7 +1759,7 @@ private int getRequiredRotation() {
     private float distance(float x0, float x1, float y0, float y1) {
         float x = x0 - x1;
         float y = y0 - y1;
-        return FloatMath.sqrt(x * x + y * y);
+        return (float) Math.sqrt(x * x + y * y);
     }
 
     /**