Move IRC config into a proper build file.

Using project('irc') doesn't work properly in a multiproject env.

Change-Id: Id4fd006efa7802e7972bf9f21c60d41ef48bceae
Reviewed-on: http://gerrit.dmdirc.com/4086
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>

build.gradle

 
 }
 
-project("irc") {
-    dependencies {
-        compile find("common")
-    }
-}
-
 task wrapper(type: Wrapper) {
     gradleVersion = '2.1'
 }

irc/build.gradle

+dependencies {
+    compile find("common")
+}