Allow Prompt Titles (instead of "Prompt 1" etc)

[sashaagafonoff]

it would be cool to allow custom titles for prompts so we can contextualise them to song/movie sections for reference - if i've got a 23 prompt movie, i can get a little lost with the "Prompt 1", "Prompt 2", etc restrictions. This would also help (you might want to concat these) in the timeline views when prompt positions are turned on.