Relicense the Velocity proxy under the terms of GPLv3 (#448)

proxy/src/main/resources/log4j2.component.properties

@@ -1,2 +1,19 @@
+#
+# Copyright (C) 2018 Velocity Contributors
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+#
+
 log4j2.contextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector
 log4j.skipJansi=true

proxy/src/main/resources/log4j2.xml

@@ -1,4 +1,21 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+    Copyright (C) 2018 Velocity Contributors
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-->
+
 <Configuration status="warn">
   <Appenders>
     <TerminalConsole name="TerminalConsole">