Update tycho version to 0.12

Following migration instructions [1].

[1] http://dev.eclipse.org/mhonarc/lists/tycho-user/msg00080.html

Change-Id: I9e54f3e7e96892b64546270cbdf0308046e1d40c
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.packaging/pom.xml

@@ -59,7 +59,7 @@
   <name>JGit Tycho Parent (Incubation)</name>
 
   <properties>
-    <tycho-version>0.11.0</tycho-version>
+    <tycho-version>0.12.0</tycho-version>
     <eclipse-site>http://download.eclipse.org/releases/galileo</eclipse-site>
   </properties>
 
@@ -91,13 +91,13 @@
   <build>
     <plugins>
       <plugin>
-        <groupId>org.sonatype.tycho</groupId>
+        <groupId>org.eclipse.tycho</groupId>
         <artifactId>tycho-maven-plugin</artifactId>
         <version>${tycho-version}</version>
         <extensions>true</extensions>
       </plugin>
       <plugin>
-        <groupId>org.sonatype.tycho</groupId>
+        <groupId>org.eclipse.tycho</groupId>
         <artifactId>target-platform-configuration</artifactId>
         <version>${tycho-version}</version>
         <configuration>
@@ -108,8 +108,8 @@
     <pluginManagement>
       <plugins>
         <plugin>
-          <groupId>org.sonatype.tycho</groupId>
-          <artifactId>maven-osgi-compiler-plugin</artifactId>
+          <groupId>org.eclipse.tycho</groupId>
+          <artifactId>tycho-compiler-plugin</artifactId>
           <version>${tycho-version}</version>
           <configuration>
             <encoding>UTF-8</encoding>
@@ -124,7 +124,7 @@
           </configuration>
         </plugin>
         <plugin>
-          <groupId>org.sonatype.tycho</groupId>
+          <groupId>org.eclipse.tycho</groupId>
           <artifactId>target-platform-configuration</artifactId>
           <version>${tycho-version}</version>
           <configuration>