Don't report errors when dependency version conflicts are found, as Gradle's default behaviour of picking the newest version is normally the right one and in practice what we've been doing anyway.

Remove RxKotlin. It doesn't add enough value over just using the RxJava API directly.

build.gradle

@@ -4,6 +4,7 @@ version '1.0-SNAPSHOT'
 apply plugin: 'java'
 apply plugin: 'kotlin'
 apply plugin: 'application'
+apply plugin: 'project-report'
 
 allprojects {
     sourceCompatibility = 1.8
@@ -42,13 +43,8 @@ configurations {
     quasar
 }
 
-// This block makes Gradle print an error and refuse to continue if we get multiple versions of the same library
-// included simultaneously.
-configurations.all() {
-    resolutionStrategy {
-        failOnVersionConflict()
-    }
-}
+// To find potential version conflicts, run "gradle htmlDependencyReport" and then look in
+// build/reports/project/dependencies/index.html for green highlighted parts of the tree.
 
 dependencies {
     compile project(':contracts')
@@ -56,26 +52,20 @@ dependencies {
     compile "com.google.code.findbugs:jsr305:3.0.1"
     compile "org.slf4j:slf4j-jdk14:1.7.13"
 
-    compile("org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version") {
-        force = true
-    }
+    compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
     compile "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
     compile "org.jetbrains.kotlin:kotlin-test:$kotlin_version"
 
-    compile("com.google.guava:guava:19.0") {
-        force = true     // Conflict between Quasar and Artemis
-    }
+    compile "com.google.guava:guava:19.0"
 
     // JOpt: for command line flags.
     compile "net.sf.jopt-simple:jopt-simple:4.9"
 
     // Quasar: for the bytecode rewriting for state machines.
-    quasar("co.paralleluniverse:quasar-core:${quasar_version}:jdk8@jar")
+    quasar "co.paralleluniverse:quasar-core:${quasar_version}:jdk8@jar"
 
     // Artemis: for reliable p2p message queues.
-    compile("org.apache.activemq:artemis-server:${artemis_version}") {
-        exclude group: "com.google.guava", module: "guava"   // Artemis is on Guava 18
-    }
+    compile "org.apache.activemq:artemis-server:${artemis_version}"
     compile "org.apache.activemq:artemis-core-client:${artemis_version}"
 
     // JAnsi: for drawing things to the terminal in nicely coloured ways.
@@ -89,9 +79,7 @@ dependencies {
     }
 
     // Force commons logging to version 1.2 to override Artemis, which pulls in 1.1.3 (ARTEMIS-424)
-    compile("commons-logging:commons-logging:1.2") {
-        force = true
-    }
+    compile "commons-logging:commons-logging:1.2"
 
     // Web stuff: for HTTP[S] servlets
     compile "org.eclipse.jetty:jetty-servlet:${jetty_version}"
@@ -116,6 +104,9 @@ dependencies {
     }
     compile "com.fasterxml.jackson.core:jackson-annotations:2.5.5"
 
+    // Coda Hale's Metrics: for monitoring of key statistics
+    compile "io.dropwizard.metrics:metrics-core:3.1.2"
+
     // Unit testing helpers.
     testCompile 'junit:junit:4.12'
     testCompile 'com.google.jimfs:jimfs:1.1'   // in memory java.nio filesystem.

core/build.gradle

@@ -35,7 +35,7 @@ dependencies {
     compile "com.google.guava:guava:19.0"
 
     // RxJava: observable streams of events.
-    compile "io.reactivex:rxkotlin:0.40.1"
+    compile "io.reactivex:rxjava:1.0.17"
 
     // Kryo: object graph serialization.
     compile "com.esotericsoftware:kryo:3.0.3"

core/src/main/kotlin/core/utilities/ProgressTracker.kt

@@ -11,7 +11,7 @@ package core.utilities
 import core.TransientProperty
 import rx.Observable
 import rx.Subscription
-import rx.lang.kotlin.BehaviourSubject
+import rx.subjects.BehaviorSubject
 import rx.subjects.PublishSubject
 import java.util.*
 
@@ -54,7 +54,7 @@ class ProgressTracker(vararg steps: Step) {
 
     /** This class makes it easier to relabel a step on the fly, to provide transient information. */
     open class RelabelableStep(currentLabel: String) : Step(currentLabel) {
-        override val changes = BehaviourSubject<Change>()
+        override val changes = BehaviorSubject.create<Change>()
 
         var currentLabel: String = currentLabel
             set(value) {