As a plugin developer you can use this plugin as dependency of your plugin by adding a dependency tag to your POM.
To add the latest version of this plugin as a maven dependency, use the following:
<dependency>
<groupId>org.jenkinsci.plugins</groupId>
<artifactId>managed-scripts</artifactId>
<version>1.6.157.v9a_ca_a_6796cf4</version>
</dependency>