add license.txt

LICENSE.txt

@@ -0,0 +1,45 @@
+Cataclysm is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/ or send a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View, California, 94041, USA.
+
+The Square font (data/font/square.ttf) is copyright Wouter van Oortmerssen, licensed under Creative Commons Attribution 3.0 Unported License. See http://strlen.com/square for more information.
+
+GNU Unifont (data/font/unitfont.ttf) is licensed under GNU General Public License v2+ with the GNU font embedding exception. Visit http://unifoundry.com/LICENSE.txt for details.
+
+Terminus Font (data/font/terminus.ttf) is licensed under the SIL Open Font License (see LICENSE-OFL-Terminus-Font.TXT).
+
+CATCH unit-test framework (tests/catch/catch.hpp) is licensed under the Boost Software License. Visit https://github.com/philsquared/Catch/blob/master/LICENSE.txt to read the license.
+
+PLF List and PLF Colony (src/list.h, src/colony.h) are licensed under the zLib license (https://www.zlib.net/zlib_license.html).
+
+getpost (tools/json_tools/format/getpost.h) is licensed under the MIT license, see file for text of license.
+
+libbacktrace is licensed under a BSD license (https://github.com/ianlancetaylor/libbacktrace/blob/master/LICENSE). The full license text is as follows:
+
+# Copyright (C) 2012-2016 Free Software Foundation, Inc.
+
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+
+#     (1) Redistributions of source code must retain the above copyright
+#     notice, this list of conditions and the following disclaimer. 
+
+#     (2) Redistributions in binary form must reproduce the above copyright
+#     notice, this list of conditions and the following disclaimer in
+#     the documentation and/or other materials provided with the
+#     distribution.  
+
+#     (3) The name of the author may not be used to
+#     endorse or promote products derived from this software without
+#     specific prior written permission.
+
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+# INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+# IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.