doc updates for text hcenter and vcenter attrs

doc/xschem_man/xschem_elements.html

@@ -89,10 +89,15 @@ p{padding: 15px  30px 10px;}
   <p>
    The <kbd>layer</kbd> property can be used
    to draw text on a different layer, for example, setting <kbd>layer=6</kbd> will draw on cyan color. 
-   A <kbd>font</kbd> property is defined to change the default font. Use only Monospaced fonts because 
-   bounding box is not correctly calculated by XSCHEM for proportional typefaces. You wil learn in the 
-   <a href="xschem_properties.html">xschem properties chapter</a> how to set, edit and change object
-   properties.
+   A <kbd>font</kbd> property is defined to change the default font.
+   A <kbd>hcenter=true</kbd> attribute may be set to center text in the reading direction, 
+   while <kbd>vcenter=true</kbd> centers text in the perpendicular (to reading) direction.
+   the 2 attributes may be set both to get full centered text box.
+  </p>
+  <img src="xschem_elements_02.png">
+  <p>
+   You wil learn in the <a href="xschem_properties.html">xschem properties chapter</a>
+   how to set, edit and change object properties.
   </p>
   <img src="xschem_texts1.png">
   <h3> SYMBOLS </h3>

xschem_library/examples/mos_power_ampli.sch

@@ -187,7 +187,7 @@ rload out 0 4
 .include \\"models_poweramp.txt\\"
 .dc vplus '-1.5' '1.5' 0.1
 .save all
-* .op
+.op
 *.probe dc v(plus,vdc)
 "}
 C {lab_wire.sym} 990 -760 0 0 {name=l1 lab=GA}