Client will now notice if the server forgets to send a reply

- Added a new catch-clause, so the client will notice if the server forgets to send a reply (sendReply(Socket, Object...)).
- Slightly improved Diffie Hellman Factory
- Added Java version to contributing guidelines

CONTRIBUTING.md

@@ -1,5 +1,12 @@
 # Contributing Guidelines
+
 ## Code Style
 - Do not use a single line for a {, but put it at the end of the previous line
-- Do not leave { or } out if possible, e.g. when writing an if statement with just one line in its body
-- Do not change the line breaks of the Javadoc
+- Do not leave { or } out even if this is possible, e.g. when writing an if statement with just one line in its body
+- Do not change the line breaks of the Javadoc
+
+## Java Version
+- Only use language features that are possible in Java 8 or earlier.
+
+
+Thank you for contributing!

src/com/blogspot/debukkitsblog/crypt/DHKeyFactory.java

@@ -10,7 +10,7 @@ public class DHKeyFactory {
 	public DHKeyFactory() {
 		System.out.println("[DHKey] Generating secure key...");
 		p = new BigInteger(2048, 12, new Random());
-		g = new BigInteger(String.valueOf(12 - new Random().nextInt(10)));
+		g = new BigInteger(String.valueOf(4 - new Random().nextInt(3)));
 		do {
 			s = new BigInteger(160, new Random());
 		} while (s.compareTo(new BigInteger("2")) == -1 || s.compareTo(p.subtract(new BigInteger("1"))) == 0);

src/com/blogspot/debukkitsblog/net/Client.java

@@ -2,6 +2,7 @@
 
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
+import java.io.EOFException;
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
@@ -438,6 +439,8 @@ public Datapackage sendMessage(Datapackage message, int timeout) {
 			if (raw instanceof Datapackage) {
 				return (Datapackage) raw;
 			}
+		} catch(EOFException ex) {
+			onLogError("[Client] Error right after sending message: EOFException (did the server forget to send a reply?)");
 		} catch (IOException | ClassNotFoundException ex) {
 			onLogError("[Client] Error while sending message");
 			ex.printStackTrace();