[bs-59] Add zip packaging for cli module

* Also added "spring" shell script (in zip), so you can
unzip it and run out of the box
* To run in developer mode use SPRING_HOME, e.g.

        $ cd spring-bootstrap-cli
        $ SPRING_HOME=target src/main/scripts/spring run samples/web.groovy
* Also added "clean" command to remove spring bootstrap grapes
(useful to force a refresh of snapshot jars)

[#48644271]

spring-bootstrap-cli/pom.xml

@@ -79,7 +79,7 @@
 				<executions>
 					<execution>
 						<id>make-distribution</id>
-						<phase>install</phase>
+						<phase>package</phase>
 						<goals>
 							<goal>single</goal>
 						</goals>