:package: Admin :: Fixed bugs (read description ↓)

Fixed bugs:
+ Pages by disabled plugins keep showing up in menu)
+ Changed 'reigsterPage' to 'registerPage'
+ Removed double <hr /> from labels page
+ Added missing language keys in english language file

Changes:
+ Added 'or none are active' to the no_plugins language string
+ Added a 'go back' button to the New Project page
+ Added a 'new project' button to the projects overview page
+ Changed 'password fields' into 'fields' for installer error page