Web code builder

Demo app about asynchronous architectures for long-response-time web applications.

It uses the next technologies:

Vertx.io in the backend.
jQuery and Dropzonejs in the frontend.
jEaSSE, my own backend implementation of Server-Sent Events for real time message subscription from the frontend to the backend.

The backend is coded in Kotlin, my brand-new favourite programming language

Quick demo

Build the project with maven:
```
 mvn package
```
Create a config.properties file that specifies your M2_HOME location, e.g.:
```
 m2.home=/home/user/.m2
```
Run the maven all-in-one jar package specifying the path to the configuration file:
```
 cd target/
 java -Dconfig=path/to/config.properties -jar codebuilder.jar
```
Go to http://localhost:8080/gui, using user as both username and password in the login screen. You will see the main screen of the application:

Drag a .zip file to the blue box, which contains the Maven pom.xml in its root folder.
Click on the "start upload" button and the upload and building process. You will see the real-time output of the process in the console:

The result files will be automatically downloaded. You can also download them by using the "Download link" anchors in the console.

As this is only a demo project, many improvements would be required for a production environment:

Provide a persistent authentication system (now for testing, user/password is hardcoded in memory)
Pack multiple-produced artifacts (JARs, WARs...) into a single zip file to avoid security warnings in some browsers.

Other tasks I will do in the near future: