Merge branch 'stable-2.7'

* stable-2.7:
  Set version to 2.7
  Fix installation of plugins
  Fix change stuck in SUBMITTED state but actually merged
  Remove documentation links from admin page
  NPE when deleting draft patch set when previous draft already deleted
  Fix example for 'test-submit rule' in Prolog cookbook
  Mark ALREADY_MERGED changes as merged in the DB and run hooks

Conflicts:
	gerrit-acceptance-tests/pom.xml
	gerrit-antlr/pom.xml
	gerrit-cache-h2/pom.xml
	gerrit-common/pom.xml
	gerrit-extension-api/pom.xml
	gerrit-gwtdebug/pom.xml
	gerrit-gwtexpui/pom.xml
	gerrit-gwtui/pom.xml
	gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AdminConstants.properties
	gerrit-httpd/pom.xml
	gerrit-launcher/pom.xml
	gerrit-main/pom.xml
	gerrit-openid/pom.xml
	gerrit-patch-commonsnet/pom.xml
	gerrit-patch-jgit/pom.xml
	gerrit-pgm/pom.xml
	gerrit-plugin-api/pom.xml
	gerrit-plugin-archetype/pom.xml
	gerrit-plugin-gwt-archetype/pom.xml
	gerrit-plugin-gwtui/pom.xml
	gerrit-plugin-js-archetype/pom.xml
	gerrit-prettify/pom.xml
	gerrit-reviewdb/pom.xml
	gerrit-server/pom.xml
	gerrit-sshd/pom.xml
	gerrit-util-cli/pom.xml
	gerrit-util-ssl/pom.xml
	gerrit-war/pom.xml
	plugins/commit-message-length-validator
	plugins/replication
	plugins/reviewnotes
	pom.xml

Change-Id: Iacb961caf52032e7e445be9ed81376db849e171b

gerrit-server/src/main/java/com/google/gerrit/server/git/MergeOp.java

@@ -509,7 +509,7 @@ public class MergeOp {
           if (rw.isMergedInto(commit, branchTip)) {
             commit.statusCode = CommitMergeStatus.ALREADY_MERGED;
             try {
-              setMergedPatchSet(chg.getId(), ps.getId());
+              setMerged(chg, null);
             } catch (OrmException e) {
               log.error("Cannot mark change " + chg.getId() + " merged", e);
             }