Merge pull request #852 from ahgittin/fix/catalog-and-icons

fixes for catalog:
add icon for kafka
improve the key used to set a user's password; key should include 'password'
Change startup so Brooklyn server binds to loopback only (not externally visible) if no web/security config is set;
this was previously a security hole for someone who didn't know what they were doing, now you have to set at least one security parameter
(e.g. users) before it will bind to 0.0.0.0, and you must set some users to log in if using the default (ExplicitUsers) security module
(it no longer defaults to admin/password either!).

https can also now be required from brooklyn.properties, using BrooklynWebConfig.HTTPS_REQUIRED;
(and if no keystore it create a default one so you can at least have encryption)

note the key for setting passwords for users has also changed, from `brooklyn.webconsole.security.explicit.user.alex` to `brooklyn.webconsole.security.user.alex.password`
(with the former still working, but deprecated)

also other tidies to config and networking also (but preserving backwards compatibility apart from the above change)
tidy logging (finally getting rid of awful jersey log messages; and use our logback.xml when cli.Main is run)