unit-tester: Drop the old unit-tester libcharon plugin

While it has some tests that we don't directly cover with the new unit tests,
most of them require special infrastructure and therefore have not been used
for a long time.

configure.ac

@@ -257,7 +257,6 @@ ARG_ENABL_SET([maemo],          [enable Maemo specific plugin.])
 ARG_ENABL_SET([radattr],        [enable plugin to inject and process custom RADIUS attributes as IKEv2 client.])
 ARG_ENABL_SET([systime-fix],    [enable plugin to handle cert lifetimes with invalid system time gracefully.])
 ARG_ENABL_SET([test-vectors],   [enable plugin providing crypto test vectors.])
-ARG_ENABL_SET([unit-tester],    [enable unit tests on IKEv2 daemon startup.])
 ARG_DISBL_SET([updown],         [disable updown firewall script plugin.])
 # programs/components
 ARG_ENABL_SET([aikgen],         [enable AIK generator.])
@@ -1326,7 +1325,6 @@ ADD_PLUGIN([maemo],                [c charon])
 ADD_PLUGIN([uci],                  [c charon])
 ADD_PLUGIN([addrblock],            [c charon])
 ADD_PLUGIN([unity],                [c charon])
-ADD_PLUGIN([unit-tester],          [c charon])
 
 AC_SUBST(charon_plugins)
 AC_SUBST(starter_plugins)
@@ -1419,7 +1417,6 @@ AM_CONDITIONAL(USE_DNSCERT, test x$dnscert = xtrue)
 AM_CONDITIONAL(USE_IPSECKEY, test x$ipseckey = xtrue)
 AM_CONDITIONAL(USE_UPDOWN, test x$updown = xtrue)
 AM_CONDITIONAL(USE_DHCP, test x$dhcp = xtrue)
-AM_CONDITIONAL(USE_UNIT_TESTS, test x$unit_tester = xtrue)
 AM_CONDITIONAL(USE_LOAD_TESTER, test x$load_tester = xtrue)
 AM_CONDITIONAL(USE_HA, test x$ha = xtrue)
 AM_CONDITIONAL(USE_KERNEL_LIBIPSEC, test x$kernel_libipsec = xtrue)
@@ -1745,7 +1742,6 @@ AC_CONFIG_FILES([
 	src/libcharon/plugins/vici/ruby/Makefile
 	src/libcharon/plugins/updown/Makefile
 	src/libcharon/plugins/dhcp/Makefile
-	src/libcharon/plugins/unit_tester/Makefile
 	src/libcharon/plugins/load_tester/Makefile
 	src/libcharon/plugins/resolve/Makefile
 	src/libcharon/plugins/attr/Makefile