revert some non needed changes from #110 (#114)

Signed-off-by: Olivier Lamy <olamy@apache.org>

Author: olamy

pom.xml

@@ -342,7 +342,6 @@ under the License.
         </configuration>
         <executions>
           <execution>
-            <?m2e execute onConfiguration,onIncremental?>
             <id>modello-cache</id>
             <goals>
               <goal>java</goal>
@@ -352,7 +351,6 @@ under the License.
             <phase>generate-sources</phase>
           </execution>
           <execution>
-            <?m2e execute onConfiguration,onIncremental?>
             <id>modello-cache-xsd</id>
             <goals>
               <goal>xsd</goal>
@@ -377,18 +375,6 @@ under the License.
         <artifactId>build-helper-maven-plugin</artifactId>
         <version>3.4.0</version>
         <executions>
-          <execution>
-            <id>add-sources</id>
-            <goals>
-              <goal>add-source</goal>
-            </goals>
-            <phase>generate-sources</phase>
-            <configuration>
-              <sources>
-                <source>${basedir}/target/generated-sources/modello</source>
-              </sources>
-            </configuration>
-          </execution>
           <execution>
             <id>add-resources</id>
             <goals>