Gradle: Add decompile task to projects (#1273)

* Gradle: Add decompile task to projects

* add ff as dependency rather than adding ti in buildsrc

* smh smh smh smh smh

* Add ff version in buildsrc build file

This doesn't work in ext as it officially isn't part of the project

* Add missing ''s

build.gradle

@@ -33,7 +33,7 @@ ext {
     asm = '7.1'
     commonsCli = '1.4'
     discord = '1.1'
-    fernflower = '20171017'
+    fernflower = '07082019'
     findbugs = '3.0.2'
     gson = '2.8.5'
     guava = '28.0-jre'
@@ -82,7 +82,7 @@ ext {
 
 allprojects {
     apply plugin: 'maven'
-    apply plugin: 'checkstyle'
+    if (this.name != 'rs-client') apply plugin: 'checkstyle'
 
     group = 'net.runelite'
     version = '1.5.33-SNAPSHOT'
@@ -105,6 +105,7 @@ subprojects {
     apply plugin: 'java-library'
     apply plugin: 'maven'
     apply plugin: "com.github.ben-manes.versions"
+    apply plugin: 'fernflower'
 
     sourceCompatibility = 1.8
     targetCompatibility = 1.8