Install wizard UI: Add preinstall hook

For fresh install, adds hook to install wizard UI to show a custom
'step' before the initial welcome screen.

Pre-install specified by providing 'cloudStack.preInstall,' which
returns a jQuery object to be displayed. It passes args.complete,
which when called will proceed to the first step of the install
wizard.
CLOUDSTACK-2628: added networkId parameter to the list of request parameters in listLoadBalancerRules API
CLOUDSTACK-2657: listTemplatePermissions API should also include the owner of the template to the list of users having permission to launch

Changes:
- Add template owner to the list of users