Fixes #976 Now uses GitHub to retrieve most current version

Reworked whole Version Checker with an extensible interface to add any other service later on easier.
The version checker now has its own config file, to collect the different options and extract them from the main config file.
In that you can specify how fine the versions should be checked.

src/main/java/appeng/services/version/DoNotCheckVersion.java

@@ -0,0 +1,25 @@
+package appeng.services.version;
+
+
+/**
+ * Exceptional template for {@link Version}, when the mod does not want a check
+ */
+public final class DoNotCheckVersion extends BaseVersion
+{
+	public DoNotCheckVersion()
+	{
+		super( Integer.MAX_VALUE, Channel.Release, Integer.MAX_VALUE );
+	}
+
+	@Override
+	public boolean isNewerAs( Version maybeOlder )
+	{
+		return true;
+	}
+
+	@Override
+	public String formatted()
+	{
+		return "dev build";
+	}
+}