Submit the Login form by the Enter key on the Email field

[MurzNN]

In the Login form usually users don't touch the Client ID and other fields, so entering the Email like this is enough:

But now we have no quick way to submit the form using keyboard after filling the Email, Enter and Ctrl+Enter keys do nothing.
So we need to use mouse or do multiple Tab presses to focus on the Login button.

To simplify this, will be good to make the form submission (pressing the Login key) using Enter key in the Email field.

[quexten]

Probably after #146

[quexten]

Actually will add this in #191

[quexten]

Done in #191.

[MurzNN]

Tried with 0.3.2 version but still doesn't work.