libnatpmp: add from oldpackages

This adds libnatpmp from old packages and updates it to version
20140401. This new version has to install the header file declspec.h.

libnatpmp is needed for tor.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

libs/libnatpmp/patches/001-install_declspec.patch

@@ -0,0 +1,11 @@
+--- a/Makefile
++++ b/Makefile
+@@ -56,7 +56,7 @@ else
+ endif
+ endif
+ 
+-HEADERS = natpmp.h
++HEADERS = natpmp.h declspec.h
+ 
+ EXECUTABLES = testgetgateway natpmpc-shared natpmpc-static
+