Added PKCS#11 token plugin stub

configure.in

@@ -145,6 +145,7 @@ ARG_ENABL_SET([padlock],        [enables VIA Padlock crypto plugin.])
 ARG_ENABL_SET([openssl],        [enables the OpenSSL crypto plugin.])
 ARG_ENABL_SET([gcrypt],         [enables the libgcrypt plugin.])
 ARG_ENABL_SET([agent],          [enables the ssh-agent signing plugin.])
+ARG_ENABL_SET([pkcs11],         [enables the PKCS11 token support plugin.])
 ARG_ENABL_SET([addrblock],      [enables RFC 3779 address block constraint support.])
 ARG_ENABL_SET([uci],            [enable OpenWRT UCI configuration plugin.])
 ARG_ENABL_SET([android],        [enable Android specific plugin.])
@@ -769,6 +770,9 @@ fi
 if test x$agent = xtrue; then
 	libstrongswan_plugins=${libstrongswan_plugins}" agent"
 fi
+if test x$pkcs11 = xtrue; then
+	libstrongswan_plugins=${libstrongswan_plugins}" pkcs11"
+fi
 if test x$gmp = xtrue; then
 	libstrongswan_plugins=${libstrongswan_plugins}" gmp"
 	pluto_plugins=${pluto_plugins}" gmp"
@@ -824,6 +828,7 @@ AM_CONDITIONAL(USE_PADLOCK, test x$padlock = xtrue)
 AM_CONDITIONAL(USE_OPENSSL, test x$openssl = xtrue)
 AM_CONDITIONAL(USE_GCRYPT, test x$gcrypt = xtrue)
 AM_CONDITIONAL(USE_AGENT, test x$agent = xtrue)
+AM_CONDITIONAL(USE_PKCS11, test x$pkcs11 = xtrue)
 
 dnl charon plugins
 dnl ==============
@@ -953,6 +958,7 @@ AC_OUTPUT(
 	src/libstrongswan/plugins/openssl/Makefile
 	src/libstrongswan/plugins/gcrypt/Makefile
 	src/libstrongswan/plugins/agent/Makefile
+	src/libstrongswan/plugins/pkcs11/Makefile
 	src/libstrongswan/plugins/test_vectors/Makefile
 	src/libhydra/Makefile
 	src/libhydra/plugins/attr/Makefile