Closes #912 (closed)
Solves #912 (closed) for slurm and hopefully all the platform files have the necessary changes. However, I have to admit I only tested for slurm and paramiko. Generalization is probably needed.
The solution consists of adding a new variable in the platform file named SCRATCH_PROJECT_DIR: chhb19 while PROJECT: hhb19. I also created a new property in the platform object: platform.project_dir which takes values of SCRATCH_PROJECT_DIR if it exists and of PROJECT if it doesn't. Then I use this variable everywhere where platform.project was used for the project directory in scratch.