Fix various typos in source documentation and comments (cont.)

Found via `codespell`

sources/editor/graphicspart/customelementgraphicpart.cpp

@@ -156,7 +156,7 @@ void CustomElementGraphicPart::setAntialiased(const bool b)
 
 /**
 	@brief CustomElementGraphicPart::stylesToXml
-	Write the curent style to xml element.
+	Write the current style to xml element.
 	The style are stored like this:
 	name-of-style:value;name-of-style:value
 	Each style separate by ; and name-style/value are separate by :
@@ -893,7 +893,7 @@ void CustomElementGraphicPart::stylesFromXml(const QDomElement &qde)
 
 /**
 	@brief CustomElementGraphicPart::resetStyles
-	Reset the curent style to default,
+	Reset the current style to default,
 	same style of default constructor
 */
 void CustomElementGraphicPart::resetStyles()

sources/editor/graphicspart/partline.cpp

@@ -606,7 +606,7 @@ QPainterPath PartLine::path() const
 
 	//debugPaint(painter);
 
-		//Determine if we must to draw extremity
+		//Determine if we must draw extremity
 	qreal reduced_line_length = line_length - (length1 * requiredLengthForEndType(first_end));
 	bool draw_1st_end = first_end && reduced_line_length >= 0;
 
@@ -685,7 +685,7 @@ QPainterPath PartLine::path() const
 			stop_point = four_points2[0];
 		}
 
-			//Adjust the end point accordint to the pen width
+			//Adjust the end point according to the pen width
 		if (pen_width && (second_end == Qet::Simple || second_end == Qet::Circle))
 			stop_point = QLineF(point1, stop_point).pointAt((line_length - (pen_width / 2.0)) / line_length);
 	}

sources/editor/graphicspart/partpolygon.cpp

@@ -499,7 +499,7 @@ void PartPolygon::removeHandler()
 
 /**
 	@brief PartPolygon::insertPoint
-	Insert a point in this polygone
+	Insert a point in this polygon
 */
 void PartPolygon::insertPoint()
 {