Add LeakCanary for debug versions of the app

app/build.gradle

@@ -33,9 +33,15 @@ android {
 
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
+        debug.java.srcDirs += 'src/debug/kotlin'
+        release.java.srcDirs += 'src/release/kotlin'
     }
 }
 
+ext {
+    leakCanaryVersion = '1.5.2'
+}
+
 dependencies {
     compile 'com.simplemobiletools:commons:2.25.3'
     compile 'joda-time:joda-time:2.9.1'
@@ -57,6 +63,8 @@ dependencies {
     }
 
     compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
+    debugCompile "com.squareup.leakcanary:leakcanary-android:$leakCanaryVersion"
+    releaseCompile "com.squareup.leakcanary:leakcanary-android-no-op:$leakCanaryVersion"
 }
 
 buildscript {

app/src/debug/kotlin/com/simplemobiletools/calendar/BuildVariantApplication.kt

@@ -0,0 +1,14 @@
+package com.simplemobiletools.calendar
+
+import com.squareup.leakcanary.LeakCanary
+
+open class BuildVariantApplication : BaseApp() {
+    override fun onCreate() {
+        super.onCreate()
+        LeakCanary.install(this);
+    }
+
+    override fun shouldInit(): Boolean {
+        return !LeakCanary.isInAnalyzerProcess(this)
+    }
+}

app/src/debug/res/values/strings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="leak_canary_display_activity_label">Calendar Leaks</string>
+</resources>

app/src/main/kotlin/com/simplemobiletools/calendar/App.kt

@@ -1,11 +1,13 @@
 package com.simplemobiletools.calendar
 
-import android.support.multidex.MultiDexApplication
 import com.facebook.stetho.Stetho
 
-class App : MultiDexApplication() {
+class App : BuildVariantApplication() {
     override fun onCreate() {
         super.onCreate()
+        if (!shouldInit()) {
+            return
+        }
         Stetho.initializeWithDefaults(this)
     }
 }

app/src/main/kotlin/com/simplemobiletools/calendar/BaseApp.kt

@@ -0,0 +1,9 @@
+package com.simplemobiletools.calendar
+
+import android.support.multidex.MultiDexApplication
+
+abstract class BaseApp : MultiDexApplication() {
+    open fun shouldInit(): Boolean {
+        return true
+    }
+}

app/src/release/kotlin/com/simplemobiletools/calendar/BuildVariantApplication.kt

@@ -0,0 +1,3 @@
+package com.simplemobiletools.calendar
+
+open class BuildVariantApplication : BaseApp()