Fixes #1932: Better VersionChecker exception handling

ModVersionFetcher will now return a MissingVersion in case of an exception
instead of letting it propagate upwards.

Also added a generic try/catch to the VersionChecker itself, just in case
any unchecked exception might be triggered inside the thread and at least
not logged correctly.

src/main/java/appeng/services/version/exceptions/InvalidRevisionException.java

@@ -0,0 +1,34 @@
+/*
+ * This file is part of Applied Energistics 2.
+ * Copyright (c) 2013 - 2015, AlgorithmX2, All rights reserved.
+ *
+ * Applied Energistics 2 is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Applied Energistics 2 is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Applied Energistics 2.  If not, see <http://www.gnu.org/licenses/lgpl>.
+ */
+
+package appeng.services.version.exceptions;
+
+
+/**
+ * Indicates a invalid revision, which does not match the pattern "rv" followed by a natural number.
+ */
+public class InvalidRevisionException extends VersionCheckerException
+{
+
+	private static final long serialVersionUID = 4828906902143875942L;
+
+	public InvalidRevisionException()
+	{
+		super( "Invalid Revision: Needs to be 'rv' followd by a natural number." );
+	}
+}