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/VersionCheckerConfig.java

@@ -0,0 +1,94 @@
+package appeng.services.version;
+
+
+import java.io.File;
+import java.util.Date;
+
+import net.minecraftforge.common.config.Configuration;
+
+
+/**
+ * Seperate config file to handle the version checker
+ */
+public final class VersionCheckerConfig
+{
+	private static final int DEFAULT_INTERVAL_HOURS = 24;
+	private static final int MIN_INTERVAL_HOURS = 0;
+	private static final int MAX_INTERVAL_HOURS = 7 * 24;
+
+	private final Configuration config;
+
+	private final boolean isEnabled;
+
+	private final String lastCheck;
+	private final int interval;
+
+	private final String level;
+
+	private final boolean shouldNotifyPlayer;
+	private final boolean shouldPostChangelog;
+
+	/**
+	 * @param file requires fully qualified file in which the config is saved
+	 */
+	public VersionCheckerConfig( File file )
+	{
+		this.config = new Configuration( file );
+
+		// initializes default values by caching
+		this.isEnabled = this.config.getBoolean( "enabled", "general", true, "If true, the version checker is enabled. Acts as a master switch." );
+
+		this.lastCheck = this.config.getString( "lastCheck", "cache", "0", "The number of milliseconds since January 1, 1970, 00:00:00 GMT of the last successful check." );
+		this.interval = this.config.getInt( "interval", "cache", DEFAULT_INTERVAL_HOURS, MIN_INTERVAL_HOURS, MAX_INTERVAL_HOURS, "Waits as many hours, until it checks again." );
+
+		this.level = this.config.getString( "level", "channel", "Beta", "Determines the channel level which should be checked for updates. Can be either Release, Beta or Alpha." );
+
+		this.shouldNotifyPlayer = this.config.getBoolean( "notify", "client", true, "If true, the player is getting a notification, that a new version is available." );
+		this.shouldPostChangelog = this.config.getBoolean( "changelog", "client", true, "If true, the player is getting a notification including changelog. Only happens if notification are enabled." );
+	}
+
+	public boolean isEnabled()
+	{
+		return this.isEnabled;
+	}
+
+	public String lastCheck()
+	{
+		return this.lastCheck;
+	}
+
+	/**
+	 * Stores the current date in milli seconds into the "lastCheck" field of the config
+	 * and makes it persistent.
+	 */
+	public void updateLastCheck()
+	{
+		final Date now = new Date();
+		final long nowInMs = now.getTime();
+		final String nowAsString = Long.toString( nowInMs );
+
+		this.config.get( "cache", "lastCheck", "0" ).set( nowAsString );
+
+		this.config.save();
+	}
+
+	public int interval()
+	{
+		return this.interval;
+	}
+
+	public String level()
+	{
+		return this.level;
+	}
+
+	public boolean shouldNotifyPlayer()
+	{
+		return this.shouldNotifyPlayer;
+	}
+
+	public boolean shouldPostChangelog()
+	{
+		return this.shouldPostChangelog;
+	}
+}