Make smack-android/smack-java7 declare minimal dependencies

smack-android/build.gradle

@@ -1,6 +1,8 @@
 description = """\
 Smack for Android.
-All the required dependencies to run Smack on Android"""
+All the required dependencies to run Smack on Android.
+Usually you want to add additional dependencies to smack-tcp,
+smack-extensions and smack-experimental."""
 
 ext {
 	smackMinAndroidSdk = 8
@@ -10,7 +12,10 @@ ext {
 // Note that the test dependencies (junit, …) are inferred from the
 // sourceSet.test of the core subproject
 dependencies {
-	androidProjects.each { project ->
+	// Filter out the optional Smack dependencies from androidProjects
+	androidProjects.findAll {
+		![':smack-tcp', ':smack-extensions', ':smack-experimental'].contains(it.getPath())
+	}.each { project ->
 		compile project
 	}
 }

smack-java7/build.gradle

@@ -1,15 +1,11 @@
 description = """\
 Smack for Java7 (or higher).
 This is a pseudo-artifact that pulls all the required dependencies to
-run Smack on Java 7 (or higher) JVMs. You can add further dependencies
-like smack-bosh, run with a minimal subset by don't depending on
-smack-java7, but using e.g. just smack-core, smack-tcp and
-smack-resolver-javax"""
+run Smack on Java 7 (or higher) JVMs. Usually you want to add additional
+dependencies to smack-tcp, smack-extensions and smack-experimental."""
 
 dependencies {
 	compile project(":smack-core")
-	compile project(":smack-extensions")
-	compile project(":smack-tcp")
 	compile project(":smack-resolver-javax")
 	compile project(":smack-sasl-javax")
 }