Replace action in text fields

[bubakazouba]

All of these sequences of actions are equal to: "replace what's in the text field with the clipboard contents":

• cmd+a, backspace, cmd+v
• cmd+a, cmd+v
• cmd+right,cmd+shift+left
• backspace[n times]
• mouse selection,backspace,cmd+v

and vice versa for copying from field

[open another bug for this] User could also be selecting only the nth word in the text field and replacing it

[bubakazouba]

one way we could implement this is to only check on the value of the field once the user de-focuses from the field or once they press enter

[bubakazouba]

Duplicate of #35