readme: simplify getting started
e2e: windows compatibility updates
browser: update tests for new login functionality

Login attempts are now allowed even without a minimum password length,
so remove test for the disablement of the submit button on login page.
browser: force username and password into login attempt

Lacking change events from some browsers when autocompleting forms, we
must manually read the values from the input elements just before
attempting to submit the credentials to the server.