Add extension command support, with test in SystemPropertyCommand and launcher-test.crank.txt

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1595220 13f79535-47bb-0310-9956-ffa450edef68
3 files changed
tree: ecd01d962b4740a6dcc9b9c532fd092239a2dee0
  1. src/
  2. default.crank.txt
  3. pom.xml
  4. sling.crank.txt