Minor string cleanup (#248)

- Simplified some strings to not include unnecessary markup.
- Fix translator comments so that they actually make it to glabels_C.ts file
      - Reconciled the style of these comments.
      - Added translator comments

glabels/ui/PropertiesView.ui

@@ -248,7 +248,7 @@
            </size>
           </property>
           <property name="toolTip">
-           <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Select another product for this gLabels project.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+           <string>Select another product for this gLabels project.</string>
           </property>
           <property name="styleSheet">
            <string notr="true">text-align:left; padding:3px;</string>
@@ -257,7 +257,8 @@
            <string>Change product</string>
           </property>
           <property name="icon">
-           <iconset theme="glabels-select-product"/>
+           <iconset theme="glabels-select-product">
+            <normaloff>.</normaloff>.</iconset>
           </property>
           <property name="iconSize">
            <size>
@@ -351,7 +352,8 @@
               <string>Horizontal orientation</string>
              </property>
              <property name="icon">
-              <iconset theme="glabels-label-orientation-horiz"/>
+              <iconset theme="glabels-label-orientation-horiz">
+               <normaloff>.</normaloff>.</iconset>
              </property>
             </item>
             <item>
@@ -359,7 +361,8 @@
               <string>Vertical orientation</string>
              </property>
              <property name="icon">
-              <iconset theme="glabels-label-orientation-vert"/>
+              <iconset theme="glabels-label-orientation-vert">
+               <normaloff>.</normaloff>.</iconset>
              </property>
             </item>
            </widget>