WIP - Comments needed - Modular/plugins approach for new item processors

[hkkenneth]

KHP-Informatics/cogstack#17 KHP-Informatics/cogstack#18

How to use:

java -Dloader.path=<PATH_TO_PLUGIN_JAR> -cp <COGSTACK_JAR> org.springframework.boot.loader.PropertiesLauncher <CONFIGS>

Reference: http://docs.spring.io/spring-boot/docs/current/api/org/springframework/boot/loader/PropertiesLauncher.html

p.s. this is needed because -jar can only work with one JAR!

Beauty:

1. Site specific features can be developed separately and loaded as JAR.
2. Plugins used completely configurable.

Ugly / To be improved:

1. Need to duplicate Document.groovy because there is no "core-lib" for these core classes in the pipeline.
2. Can we use configuration for @ComponentScan as well? Not sure about the testability.