Merge branch '579-unsubscribe-from-shared-blogs' into 'master'

Allow unsubscribing from shared blogs

Only personal blogs from non-contacts can be removed.
This also adds integration tests that check the conditions under which blogs can actually be removed.

Closes #579

See merge request !268

briar-api/src/org/briarproject/api/blogs/Blog.java

@@ -11,16 +11,13 @@ public class Blog extends Forum {
 	private final String description;
 	@NotNull
 	private final Author author;
-	private final boolean permanent;
 
 	public Blog(@NotNull Group group, @NotNull String name,
-			@NotNull String description, @NotNull Author author,
-			boolean permanent) {
+			@NotNull String description, @NotNull Author author) {
 		super(group, name, null);
 
 		this.description = description;
 		this.author = author;
-		this.permanent = permanent;
 	}
 
 	@NotNull
@@ -32,8 +29,4 @@ public class Blog extends Forum {
 	public Author getAuthor() {
 		return author;
 	}
-
-	public boolean isPermanent() {
-		return permanent;
-	}
 }

briar-api/src/org/briarproject/api/blogs/BlogFactory.java

@@ -1,7 +1,6 @@
 package org.briarproject.api.blogs;
 
 import org.briarproject.api.FormatException;
-import org.briarproject.api.contact.Contact;
 import org.briarproject.api.identity.Author;
 import org.briarproject.api.sync.Group;
 import org.jetbrains.annotations.NotNull;

briar-api/src/org/briarproject/api/blogs/BlogManager.java

@@ -20,6 +20,9 @@ public interface BlogManager {
 	Blog addBlog(LocalAuthor localAuthor, String name, String description)
 			throws DbException;
 
+	/** Returns true if a blog can be removed. */
+	boolean canBeRemoved(GroupId g) throws DbException;
+
 	/** Removes and deletes a blog. */
 	void removeBlog(Blog b) throws DbException;