Deprecate source features mojo and mark for removal

Author: laeubi

REMOVAL.MD

@@ -1,18 +1,6 @@
-## List of removals for next major version of tycho
+# List of removals for next major version of tycho
 
-# the plugin 'tycho-extras/tycho-source-feature-plugin' should be removed on next major release
+## the mojo 'tycho-source-plugin:feature-source' should be removed on next major release
 
-replaced by core tycho-source
-
-# org.eclipse.tycho.PackagingType.TYPE_ECLIPSE_REPOSITORY and org.eclipse.tycho.PackagingType.TYPE_ECLIPSE_UPDATE_SITE and corresponding mojos
-
-The packagetypes ECLIPSE_REPOSITORY+ECLIPSE_UPDATE_SITE are deprecated for a long time and should be removed, corresponding mojos and code should be dropped also
-
-# drop "fixSWT"
-
-We should simply drop this as the depending bug has be resolved for more than 5 years:
-https://bugs.eclipse.org/bugs/show_bug.cgi?id=381167
-
-# drop org.eclipse.tycho.plugins.p2.publisher.PublishProductMojo.flavor
-
-It is marked deprecated for a long time now and should be removed. removal will be backward compatible if this setting is not used.
+Source features are used for a long time to include sources in development environments but they where always brittle to use and badly integrated. As nowadays Tycho/P2 offers better ways to archive similar,
+the automatic generation of such features is deprecated and will be removed on the next release. In cases where this is still required, one should replace it with an explicitly maintained source feature in a dedicated module.

tycho-source-plugin/src/main/java/org/eclipse/tycho/source/SourceFeatureMojo.java

@@ -90,9 +90,17 @@
  * feature jar. Especially, if file <code>sourceTemplateFeature/feature.properties</code> is found,
  * values in this file override values of respective keys in
  * <code>&lt;originalFeature&gt;/feature.properties</code>.
+ * 
+ * @deprecated Source features are used for a long time to include sources in development
+ *             environments but they where always brittle to use and badly integrated. As nowadays
+ *             Tycho/P2 offers better ways to archive similar, the automatic generation of such
+ *             features is deprecated and will be removed on the next release. In cases where this
+ *             is still required, one should replace it with an explicitly maintained source feature
+ *             in a dedicated module.
  *
  */
 @Mojo(name = SourceFeatureMojo.GOAL, defaultPhase = LifecyclePhase.PACKAGE, threadSafe = true)
+@Deprecated(forRemoval = true)
 public class SourceFeatureMojo extends AbstractMojo {
 
     static final String GOAL = "feature-source";