component/mariadb: simplify mroonga installation

- move or link instead of copying
- don't set too open permissions

component/mariadb/buildout.cfg

@@ -100,8 +100,8 @@ pre-configure =
   cd fake_mariadb_source
   ln -s ${mariadb:location}/wsrep-lib
   cp -a ${mariadb:location}/include/mysql/server include
-  cp -a include/private sql
-  chmod -R a+w include sql # so that buildout can delete this compile-dir after install
+  chmod -R u+w include  # so that buildout can delete this compile-dir after install
+  mv include/private sql
   mkdir -p ${:plugin-dir}
 configure-options =
   --with-mysql-source=fake_mariadb_source
@@ -109,7 +109,7 @@ configure-options =
   --disable-static
   --disable-document
 post-install =
-  cp -ra ${mariadb:location}/lib/plugin/* ${:plugin-dir}
+  cp -rs ${mariadb:location}/lib/plugin/* ${:plugin-dir}
 plugin-dir = @@LOCATION@@/lib/plugin
 install-sql = @@LOCATION@@/share/mroonga/install.sql
 make-targets = plugindir=${:plugin-dir} install