add Python 3.7.4 difflib library with Python Software License

Author: chrissimpkins

lib/fdiff/thirdparty/PYTHON_LICENSE

@@ -0,0 +1,41 @@
+1. This LICENSE AGREEMENT is between the Python Software Foundation ("PSF"), and
+   the Individual or Organization ("Licensee") accessing and otherwise using Python
+   3.7.4 software in source or binary form and its associated documentation.
+
+2. Subject to the terms and conditions of this License Agreement, PSF hereby
+   grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce,
+   analyze, test, perform and/or display publicly, prepare derivative works,
+   distribute, and otherwise use Python 3.7.4 alone or in any derivative
+   version, provided, however, that PSF's License Agreement and PSF's notice of
+   copyright, i.e., "Copyright © 2001-2019 Python Software Foundation; All Rights
+   Reserved" are retained in Python 3.7.4 alone or in any derivative version
+   prepared by Licensee.
+
+3. In the event Licensee prepares a derivative work that is based on or
+   incorporates Python 3.7.4 or any part thereof, and wants to make the
+   derivative work available to others as provided herein, then Licensee hereby
+   agrees to include in any such work a brief summary of the changes made to Python
+   3.7.4.
+
+4. PSF is making Python 3.7.4 available to Licensee on an "AS IS" basis.
+   PSF MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.  BY WAY OF
+   EXAMPLE, BUT NOT LIMITATION, PSF MAKES NO AND DISCLAIMS ANY REPRESENTATION OR
+   WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT THE
+   USE OF PYTHON 3.7.4 WILL NOT INFRINGE ANY THIRD PARTY RIGHTS.
+
+5. PSF SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON 3.7.4
+   FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS A RESULT OF
+   MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON 3.7.4, OR ANY DERIVATIVE
+   THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.
+
+6. This License Agreement will automatically terminate upon a material breach of
+   its terms and conditions.
+
+7. Nothing in this License Agreement shall be deemed to create any relationship
+   of agency, partnership, or joint venture between PSF and Licensee.  This License
+   Agreement does not grant permission to use PSF trademarks or trade name in a
+   trademark sense to endorse or promote products or services of Licensee, or any
+   third party.
+
+8. By copying, installing or otherwise using Python 3.7.4, Licensee agrees
+   to be bound by the terms and conditions of this License Agreement.