Default to O3 (not Ofast) build mode because of gcc compiler bug in 9.2.1

See merge request !19

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91568

Warn about missing submodules, actually this time

See merge request !18

Add a warning to setup.py to make sure missing submodules don't go unnoticed

See merge request !17

Copy licenses in wheels

See merge request !16

Wrap l3dterms and h3dterms

See merge request !15

Fix uninitialized accesses to reduction variables in *_imany reductions.

Closes #3

See merge request !14

Closes #3

pytential!152 (comment 38724)

Wrap "optimized M2L" routines and helper functions

See merge request !13

Fix a variable name in setup.py

See merge request !12

[CI] Make Py3 CI version-independent

See merge request !11

Add Pytest/JUnit/Gitlab integration, add Py37 CI

See merge request inducer/pyfmmlib!10

Add a wrapper for local -> QBX local

See merge request !9

Change *formta_imany() to better support boxtree's FMM

See merge request inducer/pyfmmlib!8

* Change centers to be indexed by *INDIRECT:
   This allows using the tree's center order.
* Change rscale to be a scalar:
   This allows parallelizing by tree level.
* Add the option to generate "out_arg_only" arguments:
   This avoids creating unecessary input arrays on the user side.

Older clang doesn't support fopenmp

See merge request !7

Add remark about binary wheels to README, thank Isuru [ci skip]

See merge request inducer/pyfmmlib!6