I have just downloaded Android Studio 1.0.1 and this is the new project structure
In My Case to add external library project into android studio 1.1.0
step-1 : File -> Import Module -> set path for library project
step-2 : Set dependencies{} in main projects's build.gradle like,
dependencies {
compile project(':facebookSDK')
compile project(':slidingMenu')
compile project(':SkyconsLibrary')
}