0.28.0

What's Changed

• Improved output when trackers took a long time by @david-zwicker in #347
• Improved documentation of plotting by @david-zwicker in #348
• Updated version of sphinx-rtd-theme by @david-zwicker in #349
• Updated logos by @david-zwicker in #350
• Test scipy solver for field collections by @david-zwicker in #352
• Fix matplotlib warning by @david-zwicker in #356
• Improve error message when numba_mpi is not found by @david-zwicker in #357
• Improved documentation by @david-zwicker in #359
• Mostly improvements of documentation by @david-zwicker in #361
• More detailed table of contents in PDF manual by @david-zwicker in #362
• Protect periodic attribute of grids by @david-zwicker in #363
• Improved operator handling by @david-zwicker in #369
• Extended expression BCs to also accept python functions by @david-zwicker in #370
• Improved check of functions setting BCs by @david-zwicker in #371
• Added tighter check to dot product operator by @david-zwicker in #373
• Generalized inner product operator by @david-zwicker in #374
• Added additional checks to new implementation of operators by @david-zwicker in #377

Full Changelog: 0.27.1...0.28.0