Add plugin and test to reproduce failing tests since c9fe9af

With all the change and revert mess of the HOOK_BASEFS_UP tests started
failing due to usr.so and sys.so failed to set up their conditions.  It
then became clear that boomisc.so cleaned up /run ... with the revert
we got service_register() to be called before global_rlimit[] was setup
causing services registered by plugins, before conf_init(), to crash.

This plugin and test is here to ensure we catch this problem in case of
any future refactor.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

plugins/Makefile.am

@@ -41,6 +41,10 @@ if BUILD_RTC_PLUGIN
 libplug_la_SOURCES += rtc.c
 endif
 
+if BUILD_TESTSERV_PLUGIN
+libplug_la_SOURCES += testserv.c
+endif
+
 if BUILD_TTY_PLUGIN
 libplug_la_SOURCES += tty.c
 endif
@@ -92,6 +96,10 @@ if BUILD_RTC_PLUGIN
 pkglib_LTLIBRARIES += rtc.la
 endif
 
+if BUILD_TESTSERV_PLUGIN
+pkglib_LTLIBRARIES += testserv.la
+endif
+
 if BUILD_TTY_PLUGIN
 pkglib_LTLIBRARIES += tty.la
 endif