Moved agent status computation to a model virtual.

Updated views to reflect change in names.
Renamed agentlist directive files.

Updated references to properly inject directive and template.

Motivation: to add more agent-specific directives in same directive file
and remain clear and concise with file structure.
Created the agent-status directive.

Displays the agent's status (cash, securities value, total value).

Integrated this directive into agent-list directive and agent view.
Added action buttons to agent list directive.
Added ability to pass in league id for agent creation.

Sets default value for league in league selection dropdown.
Integrated agents list into users.
Added agent list to leagues.
Some header navigation improvements.