Move connections to top and fix anchor warning
Fix login failed notification not being shown
Improve host string parsing
Improve handling of login errors
New page for settings with the option of resetting the host settings

Also, show a popup for invalid URLs
Read to-be-verified hostname from QUrl and reset the hoststring to its default
Don't instantiate the QWebdav object from main()

Instead, let the browser handle the lifecycle of the object.
This also gets rid of false auth credentials after resetting the remote host settings.