improvements in popup page

[xerosanyam]

• when popup opens, input box should have focus, ie user should be able to type directly without extra mouse click
• add labels to input boxes
• dumb down the ui. it is unclear what lot of things do
  • what is the purpose of lock?
    • would it be more intuitive if it were a checkbox?
  • make it easy to update the dynamic url
    • what if we segment each url parameter into an input box of its own
• add loading states
  • while logging in, while creating a short link - wherever an api call is involved