License: cover contrib/pgcrypto/crypt-md5.c

crypt-md5.c is inherited from PostgreSQL and says only that it was
imported from FreeBSD, written by Poul-Henning Kamp.  LICENSE did not
mention it.  This was found while checking 2.2.0-incubating-rc3.

The FreeBSD revision the file names, src/lib/libcrypt/crypt-md5.c 1.5,
carried Kamp's beer-ware notice, which asks that the notice be retained.
Reproduce that notice in licenses/LICENSE-beerware-crypt-md5.txt and
list the file under it.  FreeBSD's copy was later re-released under the
2-clause BSD license (FreeBSD commit d8e82636a47b), and LICENSE mentions
that too.

Exclude the new licence file from RAT like the other verbatim licence
texts.

Assisted-by: Claude Code

Author: tuhaihe

LICENSE

@@ -478,6 +478,17 @@ The PostgreSQL software includes:
       notices; they are reproduced in:
       see licenses/LICENSE-dmetaphone.txt
 
+----------------------------
+   Beer-ware License (Revision 42)
+
+      MD5-based crypt() from FreeBSD, written by Poul-Henning Kamp:
+      contrib/pgcrypto/crypt-md5.c
+      The file keeps only a note that it was imported from FreeBSD.  The
+      notice that FreeBSD's copy carried is reproduced in:
+      see licenses/LICENSE-beerware-crypt-md5.txt
+      FreeBSD's version of the file was later re-released under the
+      2-clause BSD license.
+
 ================================================================================
 This product contains significant parts that were originally based on software
 from VMware, Inc. or its affiliates.

licenses/LICENSE-beerware-crypt-md5.txt

@@ -0,0 +1,9 @@
+contrib/pgcrypto/crypt-md5.c was imported into PostgreSQL from FreeBSD's
+src/lib/libcrypt/crypt-md5.c, revision 1.5, which carried this notice:
+
+----------------------------------------------------------------------------
+"THE BEER-WARE LICENSE" (Revision 42):
+<phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
+can do whatever you want with this stuff. If we meet some day, and you think
+this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
+----------------------------------------------------------------------------

pom.xml

@@ -1884,6 +1884,7 @@ code or new licensing patterns.
                 they carry no license header of their own.
             -->
             <exclude>licenses/LICENSE-amalgamate.txt</exclude>
+            <exclude>licenses/LICENSE-beerware-crypt-md5.txt</exclude>
             <exclude>licenses/LICENSE-boost.txt</exclude>
             <exclude>licenses/LICENSE-erand48.txt</exclude>
             <exclude>licenses/LICENSE-geqo.txt</exclude>