Distributable JAR build

- connection manager should now be rock stable
- does try to create new connections as long as there are less than eight active connections, which might result in more than eight outgoing connections, but this shouldn't be a problem
- some minor improvements and bug fixes

demo/build.gradle

@@ -1,4 +1,10 @@
-apply plugin: 'java'
+plugins {
+    id "us.kirchmeier.capsule" version "1.0-rc1"
+}
+
+task fatCapsule(type: FatCapsule) {
+    applicationClass 'ch.dissem.bitmessage.demo.Main'
+}
 
 sourceCompatibility = 1.7
 version = '0.0.1'