[UX] Make login page more intuitive

[michaelstingl]

I found some minor glitches on the login page of the 3.5.3 ownCloud iOS app:

1) "Done" Button?

The 3 input fields on the login page feels like a form, and a "Next" button to navigate to the next input field would be more convenient.

2) Field Focus

A click on the "Username" field should place the cursor in the field.

3) Scroll Down?

I moved the page upwards 5 Seconds ago, why does it scroll down now?

4) Button Inactive

After entering the first character in the "Password" field, the "Log in" button should be activated and clickable.

5) Click?

A click to activate the "Log in" button shouldn't be necessary. It should immediately send the login request to the ownCloud server.

6) Click Again?

… wouldn't be necessary.

Tested on iPhone 5s running iOS 10.3.1.

00007354

[mmattel]

👍 really needs improvment

[nasli]

All the login view is going to be refactored in next versions. We keep in mind for the new login view thanks @michaelstingl !

[nasli]

Fixed via #919