Refactor / redesign issue e-mails (BB-15886)

These emails have "view the issue" and "unsubscribe from issue" links which are too close.
Sometimes I click unsubscribe instead of view.
What is good even in that case, it opens bitbucket page and shows balloon "you are unsubscribed" with undo link. The bad thing that this baloon stays only for 5 seconds.

Suggest 1: keep baloon with undo link forever on this page until reload
Suggest 2: Move "unsubscribe" to another corner of email layout, say to right-bottom (and keep "view issue" at left bottom).

p.s. When I entered this text I dediced to attach image. I prepared screenshot and dragged it's file to "Attachment" field of the form. Opps, it didnt got the file to the input field, and instead opened it in browser. Ok, the controls seems to be non-standard. Then I clicked back button and ooops - all form text is lost. Please make standard file control in the form, or keep the form text..