Added input-popup window, started filling in textfields, labels and buttons

src/main/java/com/application/GUI/Input.java

src/main/java/com/application/Main.java

src/main/resources/com.application/CSS/styleSheet.css

target/classes/com.application/CSS/styleSheet.css

target/classes/com/application/GUI/Input.class

target/classes/com/application/Main$1WorkerThread.class

target/classes/com/application/Main.class