Sets are built in types
Whitespace tweaks
get_real_user is not called from anywhere
No need for try-except
This is only called here
Don't check is_installed for each dependee
No more run orders in shutit_map
shutit_map_list -> shutit_id_list
Don't modify lists in place - it could mess up ordering
Clarify some code now we have module id
Use conventional syntax for dictionary keys

This will error if the key doesn't exist, which is probably the best
option
Merge branch 'aphs-cleanup-run-order' of https://github.com/aidanhs/shutit into aidanhs-aphs-cleanup-run-order