menuselect: Add DragonFly BSD.

In DragonFly BSD, added libraries from ports are placed into /usr/local.
Therefore, this directory must be added for the preprocessor, compiler, and
linker.

Beside that, the script ./configure was updated:
* OSARCH list was outdated and not used, removed.
* AC_CANONICAL_BUILD was not used.
* _REENTRANT, this feature test macro is obsolete.

ASTERISK-27820

Change-Id: I186d88d99cfa4de6569888e12ac97bd2f441c422

menuselect/configure

@@ -2320,33 +2320,18 @@ case $host_os in *\ *) host_os=`echo "$host_os" | sed 's/ /-/g'`;; esac
 HOST_OS=${host_os}
 
 
-PBX_WINARCH=0
 case "${host_os}" in
-     freebsd*)
-     OSARCH=FreeBSD
+     *dragonfly*)
+     CPPFLAGS="${CPPFLAGS} -I/usr/local/include"
+     LDFLAGS="${LDFLAGS} -L/usr/local/lib"
      ;;
-     netbsd*)
-     OSARCH=NetBSD
+     *netbsd*)
+     CPPFLAGS="${CPPFLAGS} -I/usr/pkg/include"
+     LDFLAGS="${LDFLAGS} -L/usr/pkg/lib"
      ;;
-     openbsd*)
-     OSARCH=OpenBSD
-     ;;
-     solaris*)
-     OSARCH=SunOS
-     ;;
-     mingw32)
-     OSARCH=mingw32
-     PBX_WINARCH=1
-     ;;
-     cygwin)
-     OSARCH=cygwin
-     PBX_WINARCH=1
-     ;;
-     linux-gnueabi)
-     OSARCH=linux-gnu
-     ;;
-     *)
-     OSARCH=${host_os}
+     *bsd*)
+     CPPFLAGS="${CPPFLAGS} -I/usr/local/include"
+     LDFLAGS="${LDFLAGS} -L/usr/local/lib"
      ;;
 esac