Add libjwt to third-party

The current STIR/SHAKEN implementation is not currently usable due
to encryption issues. Rather than trying to futz with OpenSSL and
the the current code, we can take advantage of the existing
capabilities of libjwt but we first need to add it to the
third-party infrastructure already in place for jansson and
pjproject.

A few tweaks were also made to the third-party infrastructure as
a whole.  The jansson "dest" install directory was renamed "dist"
to better match convention, and the third-party Makefile was updated
to clean all product directories not just the ones currently in
use.

Resolves: #349
(cherry picked from commit d7a6116681)

menuselect/autoconfig.h.in

@@ -4,13 +4,19 @@
 #define MENUSELECT_AUTOCONFIG_H
 
 
-/* Define to 1 if using 'alloca.c'. */
+/* Define to one of `_getb67', `GETB67', `getb67' for Cray-2 and Cray-YMP
+   systems. This function is required for `alloca.c' support on those systems.
+   */
+#undef CRAY_STACKSEG_END
+
+/* Define to 1 if using `alloca.c'. */
 #undef C_ALLOCA
 
-/* Define to 1 if you have 'alloca', as a function or macro. */
+/* Define to 1 if you have `alloca', as a function or macro. */
 #undef HAVE_ALLOCA
 
-/* Define to 1 if <alloca.h> works. */
+/* Define to 1 if you have <alloca.h> and it should be used (not on Ultrix).
+   */
 #undef HAVE_ALLOCA_H
 
 /* Define to 1 if you have the `asprintf' function. */
@@ -31,6 +37,9 @@
 /* Define if your system has the LIBXML2 libraries. */
 #undef HAVE_LIBXML2
 
+/* Define to 1 if you have the <memory.h> header file. */
+#undef HAVE_MEMORY_H
+
 /* Define to 1 if you have the ncurses library. */
 #undef HAVE_NCURSES
 
@@ -43,9 +52,6 @@
 /* Define to 1 if you have the <stdint.h> header file. */
 #undef HAVE_STDINT_H
 
-/* Define to 1 if you have the <stdio.h> header file. */
-#undef HAVE_STDIO_H
-
 /* Define to 1 if you have the <stdlib.h> header file. */
 #undef HAVE_STDLIB_H
 
@@ -111,9 +117,7 @@
 	STACK_DIRECTION = 0 => direction of growth unknown */
 #undef STACK_DIRECTION
 
-/* Define to 1 if all of the C90 standard headers exist (not just the ones
-   required in a freestanding environment). This macro is provided for
-   backward compatibility; new code need not use it. */
+/* Define to 1 if you have the ANSI C header files. */
 #undef STDC_HEADERS
 
 /* Define to `unsigned int' if <sys/types.h> does not define. */