the setup script should setup 1 sstate for all build folders, not 1 per build

[ndechesne]

Now that we have support for multiple build folders, it would be more optimal to setup a single sstate shared across all of them. In case the same DISTRO/MACHINE are built in multiple places.

we should also provide a script to cleanup the sstate in a proper way

[twoerner]

This is a 2-part issue. Has the first part (common sstate) been satisfied? The "scripts" folder in openembedded-core contains several scripts which pertain to sstate, do any of these satisfy your requirements, or are you looking for something else?