Add support for Nikon Coolpix P340

[ghost]

From darktable 1.6.6 I have the following output

$ darktable
RawSpeed:Unable to find camera in database: NIKON COOLPIX P340 
[rawspeed] Camera 'NIKON' 'COOLPIX P340', mode '' not supported, and not allowed to guess. Sorry.

Can I provide more info to help solve the problem?

[pedrocr]

Supplying a raw sample is usually enough. Providing one to rawsamples.ch insures the camera will stay supported in the future. You can also just open a new camera support bug report in the darktable redmine:

https://www.darktable.org/redmine/projects/darktable/issues/new

For darktable support more than rawspeed is needed and when we add the rawspeed support we also submit it here to be integrated.