Make plugins and polling configurable

* Move PluginConfig out of bramble-android. Projects using bramble now need to provide it.
* Add a PluginConfig#shouldPoll() method which can be used to disable polling altogether.
* Move Poller instantiation to the PluginManager.

bramble-core/src/main/java/org/briarproject/bramble/plugin/PluginManagerImpl.java

@@ -8,6 +8,7 @@ import org.briarproject.bramble.api.lifecycle.Service;
 import org.briarproject.bramble.api.lifecycle.ServiceException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionManager;
+import org.briarproject.bramble.api.plugin.ConnectionRegistry;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.PluginConfig;
@@ -29,8 +30,11 @@ import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.SettingsManager;
+import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.system.Scheduler;
 import org.briarproject.bramble.api.ui.UiCallback;
 
+import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
@@ -40,6 +44,7 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executor;
+import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
 
@@ -57,11 +62,15 @@ class PluginManagerImpl implements PluginManager, Service {
 			Logger.getLogger(PluginManagerImpl.class.getName());
 
 	private final Executor ioExecutor;
+	private final ScheduledExecutorService scheduler;
 	private final EventBus eventBus;
 	private final PluginConfig pluginConfig;
 	private final ConnectionManager connectionManager;
+	private final ConnectionRegistry connectionRegistry;
 	private final SettingsManager settingsManager;
 	private final TransportPropertyManager transportPropertyManager;
+	private final SecureRandom random;
+	private final Clock clock;
 	private final UiCallback uiCallback;
 	private final Map<TransportId, Plugin> plugins;
 	private final List<SimplexPlugin> simplexPlugins;
@@ -70,22 +79,30 @@ class PluginManagerImpl implements PluginManager, Service {
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
 	@Inject
-	PluginManagerImpl(@IoExecutor Executor ioExecutor, EventBus eventBus,
+	PluginManagerImpl(@IoExecutor Executor ioExecutor,
+			@Scheduler ScheduledExecutorService scheduler, EventBus eventBus,
 			PluginConfig pluginConfig, ConnectionManager connectionManager,
+			ConnectionRegistry connectionRegistry,
 			SettingsManager settingsManager,
 			TransportPropertyManager transportPropertyManager,
+			SecureRandom random, Clock clock,
 			UiCallback uiCallback) {
 		this.ioExecutor = ioExecutor;
+		this.scheduler = scheduler;
 		this.eventBus = eventBus;
 		this.pluginConfig = pluginConfig;
 		this.connectionManager = connectionManager;
+		this.connectionRegistry = connectionRegistry;
 		this.settingsManager = settingsManager;
 		this.transportPropertyManager = transportPropertyManager;
+		this.random = random;
+		this.clock = clock;
 		this.uiCallback = uiCallback;
 		plugins = new ConcurrentHashMap<>();
 		simplexPlugins = new CopyOnWriteArrayList<>();
 		duplexPlugins = new CopyOnWriteArrayList<>();
 		startLatches = new ConcurrentHashMap<>();
+
 	}
 
 	@Override
@@ -123,6 +140,13 @@ class PluginManagerImpl implements PluginManager, Service {
 				ioExecutor.execute(new PluginStarter(d, startLatch));
 			}
 		}
+		// Instantiate the poller
+		if (pluginConfig.shouldPoll()) {
+			LOG.info("Starting poller");
+			Poller poller = new Poller(ioExecutor, scheduler, connectionManager,
+					connectionRegistry, this, random, clock);
+			eventBus.addListener(poller);
+		}
 	}
 
 	@Override

bramble-core/src/main/java/org/briarproject/bramble/plugin/PluginModule.java

@@ -26,8 +26,6 @@ public class PluginModule {
 	public static class EagerSingletons {
 		@Inject
 		PluginManager pluginManager;
-		@Inject
-		Poller poller;
 	}
 
 	@Provides
@@ -35,19 +33,6 @@ public class PluginModule {
 		return new BackoffFactoryImpl();
 	}
 
-	@Provides
-	@Singleton
-	Poller providePoller(@IoExecutor Executor ioExecutor,
-			@Scheduler ScheduledExecutorService scheduler,
-			ConnectionManager connectionManager,
-			ConnectionRegistry connectionRegistry, PluginManager pluginManager,
-			SecureRandom random, Clock clock, EventBus eventBus) {
-		Poller poller = new Poller(ioExecutor, scheduler, connectionManager,
-				connectionRegistry, pluginManager, random, clock);
-		eventBus.addListener(poller);
-		return poller;
-	}
-
 	@Provides
 	@Singleton
 	ConnectionManager provideConnectionManager(

bramble-core/src/main/java/org/briarproject/bramble/plugin/Poller.java

@@ -54,7 +54,6 @@ class Poller implements EventListener {
 	private final Lock lock;
 	private final Map<TransportId, ScheduledPollTask> tasks; // Locking: lock
 
-	@Inject
 	Poller(@IoExecutor Executor ioExecutor,
 			@Scheduler ScheduledExecutorService scheduler,
 			ConnectionManager connectionManager,