init-dired.el: Fix indentation
Use projectile-command-map, not projectile-mode-map

This avoids hard coding the prefix key.
Add projectile-copy-project-filename-as-kill
Set magit-popup-use-prefix-argument to default
init-snakemake.el: Fix indentation
Replace some error calls with user-error calls
Give compile commands their own prefix map
Add recompile-current-compilation