* Use pytential branch

* Refactor E2P

* try new loopy branch

* fix formatting

* disable domains check

* register only if not found

* Move kernel_scaling to the outer kernel

* Refactor P2E

* Use loopy main

* re-enable implemented domains check

* Rename some loopy kernel handling functions

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Co-authored-by: Andreas Kloeckner <inform@tiker.net>

* Move derivative taker to a separate file

* Add fold markers

* fix docs

* Merge local_isrc and local_isrc_strength and tag as vec for coalescced access

* Use new name

* Add an explanation about the optimization

* Back to loopy main with renamed transform

Co-authored-by: Andreas Kloeckner <inform@tiker.net>

* Optimize M2L for GPU

* Move icoeff_tgt to top level iname

* Fix substitution

* use loopy branch

* remove unused imports

* go back to loopy main

* Reduce diff

* move all optimizations to m2l_translation

* Remove extraneous FIXME

Co-authored-by: Andreas Klöckner <inform@tiker.net>