Merge of all branches of Fabian PK (related to skills)

• Merge improved SkillManagerGUI from Tobias Bodmer
• Fix aron code generation for classes without members

@reister. YOu only need to review the changes to aron (Generator.cpp)

Depends on MR armarx-core!246 (merged)

Includes MR !285 (closed) and !320 (closed)

source/RobotAPI/components/skills/SkillProviderExample/aron/HelloWorldAcceptedType.xml

 <?xml version="1.0" encoding="UTF-8" ?>
 <AronTypeDefinition>
     <GenerateTypes>
+        <IntEnum name="HelloWorldInteEnum">
+            <EnumValue key="INT_ENUM_VALUE_0" value="0" />
+            <EnumValue key="INT_ENUM_VALUE_1" value="1" />
+            <EnumValue key="INT_ENUM_VALUE_2" value="2" />
+            <EnumValue key="INT_ENUM_VALUE_3" value="3" />
+            <EnumValue key="INT_ENUM_VALUE_4" value="4" />
+            <EnumValue key="INT_ENUM_VALUE_5" value="5" />
+            <EnumValue key="INT_ENUM_VALUE_6" value="6" />
+            <EnumValue key="INT_ENUM_VALUE_7" value="7" />
+            <EnumValue key="INT_ENUM_VALUE_8" value="8" />
+        </IntEnum>
         <Object name='armarx::skills::Example::HelloWorldAcceptedType'>
             <ObjectChild key='some_int'>
                 <Int />
@@ -18,9 +29,15 @@
                 </List>
             </ObjectChild>
 
-            <!--<ObjectChild key='some_matrix'>
+            <ObjectChild key='some_dict_of_matrices'>
+                <Dict>
+                    <Matrix rows="3" cols="3" type="float32" />
+                </Dict>
+            </ObjectChild>
+
+            <ObjectChild key='some_matrix'>
                 <Matrix rows="3" cols="3" type="float32" />
-            </ObjectChild>-->
+            </ObjectChild>
 
         </Object>
     </GenerateTypes>