Fix/version bump 0.6.0 snapshot

- Fix change-version.sh
-- previously excluded any file contain log or war, rather than just .log and .war
-- previously excluded any file with "." in a dir on its path, rather than just . at the start of dir name

- Update version to 0.6.0-SNAPSHOT for missed files
-- Adds BROOKLYN_VERSION marker to:
--- docs/use/guide/quickstart/catalog.xml
--- usage/dist/src/main/dist/conf/catalog.xml
--- util/jmx/jmxrmi-agent/src/main/java/brooklyn/util/jmx/jmxrmi/JmxRmiAgent.java

Note that for the first two, the path is to a snapshot repo so the URLs will only work if the new version is for a snapshot release!