A panorama can be made up of 15 or more different photos, 'manipulated' together... sometimes you have to clone out duplicate 'moving' objects and fill up missing pieces. So, is a panorama manipulated photography..?
Using a flash or artificial lighting, is that manipulation..? (you talked about darkroom work, but not about what happens before you take the picture...).
I know you can add lots of other things to the discussion, like getting people to pose for you, putting a still life together, using filters on your camera, etc...
I only brought up these things to make clear that there is manipulation in everything we do, from the moment we pick up a camera.
An interesting article about this subject can be found here
It seems that photojournalism is bound by strict rules about photo manipulation... Understandably...

We do not see things as they are. ǝɹɐ ǝʍ sɐ sƃuıɥʇ ǝǝs ǝʍ