- general code clean up

- removed repetitive code (checks using $this->is_loggedin())
- updated the main README to include the latest added functions/methods

README.md

@@ -153,6 +153,7 @@ The class currently supports the following functions/methods to GET/POST/PUT/DEL
 - list_events()
 - list_extension()
 - list_firewallgroups()
+- list_firmware()
 - list_guests()
 - list_health()
 - list_hotspotop()
@@ -164,6 +165,7 @@ The class currently supports the following functions/methods to GET/POST/PUT/DEL
 - list_radius_accounts() (supported on controller version 5.5.19 and higher)
 - list_radius_profiles()
 - list_rogueaps()
+- list_routing()
 - list_self()
 - list_settings()
 - list_sites()