add icons for line style

- also break a too long tooltip

src/Mod/TechDraw/Gui/DlgPrefsTechDraw3.ui

@@ -515,31 +515,55 @@
            <property name="text">
             <string>NeverShow</string>
            </property>
+           <property name="icon">
+            <iconset resource="Resources/TechDraw.qrc">
+             <normaloff>:/icons/arrownone.svg</normaloff>:/icons/arrownone.svg</iconset>
+           </property>
           </item>
           <item>
            <property name="text">
             <string>Continuous</string>
            </property>
+           <property name="icon">
+            <iconset resource="Resources/TechDraw.qrc">
+             <normaloff>:/icons/continuous-line.svg</normaloff>:/icons/continuous-line.svg</iconset>
+           </property>
           </item>
           <item>
            <property name="text">
             <string>Dash</string>
            </property>
+           <property name="icon">
+            <iconset resource="Resources/TechDraw.qrc">
+             <normaloff>:/icons/dash-line.svg</normaloff>:/icons/dash-line.svg</iconset>
+           </property>
           </item>
           <item>
            <property name="text">
             <string>Dot</string>
            </property>
+           <property name="icon">
+            <iconset resource="Resources/TechDraw.qrc">
+             <normaloff>:/icons/dot-line.svg</normaloff>:/icons/dot-line.svg</iconset>
+           </property>
           </item>
           <item>
            <property name="text">
             <string>DashDot</string>
            </property>
+           <property name="icon">
+            <iconset resource="Resources/TechDraw.qrc">
+             <normaloff>:/icons/dashDot-line.svg</normaloff>:/icons/dashDot-line.svg</iconset>
+           </property>
           </item>
           <item>
            <property name="text">
             <string>DashDotDot</string>
            </property>
+           <property name="icon">
+            <iconset resource="Resources/TechDraw.qrc">
+             <normaloff>:/icons/dashDotDot-line.svg</normaloff>:/icons/dashDotDot-line.svg</iconset>
+           </property>
           </item>
          </widget>
         </item>
@@ -986,11 +1010,19 @@
            <property name="text">
             <string>Continuous</string>
            </property>
+           <property name="icon">
+            <iconset resource="Resources/TechDraw.qrc">
+             <normaloff>:/icons/continuous-line.svg</normaloff>:/icons/continuous-line.svg</iconset>
+           </property>
           </item>
           <item>
            <property name="text">
             <string>Dashed</string>
            </property>
+           <property name="icon">
+            <iconset resource="Resources/TechDraw.qrc">
+             <normaloff>:/icons/dash-line.svg</normaloff>:/icons/dash-line.svg</iconset>
+           </property>
           </item>
          </widget>
         </item>

src/Mod/TechDraw/Gui/DlgPrefsTechDraw4.ui

@@ -42,7 +42,8 @@
            </font>
           </property>
           <property name="toolTip">
-           <string>Shape of line end caps. Only change unless you know what you are doing!</string>
+           <string>Shape of line end caps.
+Only change unless you know what you are doing!</string>
           </property>
           <property name="prefEntry" stdset="0">
            <cstring>EdgeCapStyle</cstring>

src/Mod/TechDraw/Gui/Resources/TechDraw.qrc

@@ -91,6 +91,11 @@
         <file>icons/arrow-down.svg</file>
         <file>icons/arrow-ccw.svg</file>
         <file>icons/arrow-cw.svg</file>
+        <file>icons/continuous-line.svg</file>
+        <file>icons/dot-line.svg</file>
+        <file>icons/dashDot-line.svg</file>
+        <file>icons/dashDotDot-line.svg</file>
+        <file>icons/dash-line.svg</file>
         <file>icons/techdraw-lock.png</file>
         <file>icons/cursor-balloon.png</file>
         <file>icons/none.svg</file>