This commit adds a new starter named spring-boot-starter-shell-crsh and auto configuration support to embed a system shell within Spring Boot applications.
The embedded shell allows clients to connect via ssh or telnet to the Boot app and execute commands. Commands can be implemented and embedded with app.
For sample usage see spring-boot-samples-actuator.
Rework main build POM to be an aggregator pom that does not inherit
from any parent. Introduce new spring-boot-dependencies module to
act as a parent for both spring-boot-starter-parent and
spring-boot-parent.
