* fix: more imports cleanup and formatting
* add: hair shape (from old MaterialStrand for now)
* add: pixel / Non Blender units strand width
* fix: an exception handling of df3_library
* fix: gas flow_type typo
Those were breaking automated tests, since (un)registering was not
working properly. Mainly:
* Use `hasattr` instead of try/except when batch-assigning to a variable
that does not always exist.
* Fix some incorrect call to sub-`register()` from parent `unregister()`
functions.
* Remove double definition (in two different files) of World's pov
textures.
* Moved: some existing functions into new separate files to improve code
readability (detailed in __init__.py docstring)
* Remove: max_intersections deprecated in pov 3.8
* Add: Validate utf-8 characters with specific API function at session's
first script init
* Add : Icons to some text fields and inviting labels
* Change default camera normal perturbation value to non zero since its
use is first driven by a boolean toggle
* Change: lists (vectors and indices) are now exported in one line by
default for better manual scene overview and debugging
* Change: a couple of tooltips corrections
* Change : renamed many variables and functions to snake_case according
to recommanded style guides
* Fix : Heightfield primitive (forward slashes were expected for
displacement texture path)
* Fix : Text nippet insertion operator
* Fix : added console print tip to check executable path on failure to
process
* Fix : tweaked finished render say command for Linux
* Fix : interface of some shader nodes broken since 2.8 api changes
* Fix : export hair particles
