use a BOM for Eclipse based products

centralize properties of eclipse based product (ie. p2.url,...) in a
single bill of materials file

contributes to gemoc/gemoc-discussions#6

Signed-off-by: Didier Vojtisek <didier.vojtisek@inria.fr>

.gitignore

@@ -2,3 +2,4 @@ bin/
 **/xtend-gen/
 **/*.class
 **/target/
+**/.polyglot.*

pom.xml

@@ -8,21 +8,16 @@
     <artifactId>org.eclipse.gemoc.execution.sequential.java.root</artifactId>
     <version>4.0.0-SNAPSHOT</version>
     <packaging>pom</packaging>    
-
+	<parent>
+		<groupId>org.eclipse.gemoc.gemoc-studio</groupId>
+		<artifactId>gemoc_studio-eclipse-bom</artifactId>
+		<version>3.3.0-SNAPSHOT</version>
+		<relativePath>../gemoc-studio/gemoc_studio/plugins/gemoc_studio-eclipse-bom</relativePath>
+	</parent>
     <properties>
-		<tycho-version>2.2.0</tycho-version>
-    	<xtend.version>2.24.0</xtend.version>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<tycho.scmUrl>scm:git:https://github.com/eclipse/gemoc-studio-execution-java.git</tycho.scmUrl>
 		<!-- <sonar.projectKey>gemoc:${project.groupId}:${project.artifactId}</sonar.projectKey>-->	
 
-		<eclipse.release.p2.url>http://download.eclipse.org/releases/2020-12</eclipse.release.p2.url>
-		<k3.p2.url>http://www.kermeta.org/k3/update</k3.p2.url>
-		<melange.p2.url>http://melange.inria.fr/updatesite/nightly/update_2020-11-16</melange.p2.url>
-		<elk.p2.url>http://download.eclipse.org/elk/updates/releases/0.7.1</elk.p2.url>
-		<aspectJ.p2.url>http://download.eclipse.org/tools/ajdt/410/dev/update</aspectJ.p2.url>
-<!--		<sirius.p2.url>https://download.eclipse.org/sirius/updates/releases/6.1.3/photon</sirius.p2.url>-->
-
 		<maven.deploy.skip>false</maven.deploy.skip>
 	</properties>