blendfile.py: fix/add some 'basic data' reading (mostly arrays of ints/floats/...), add utils to recursively get all items of a struct.

New `BlendFileBlock.items_recursive_iter()` will yield all valid key/values pair of a given struct,
including sub ones (e.g. 'id.next', 'id.name', etc.).

Also sort each category

Less verbose and cleaner imho.

This tool aims at exporting (parts of) a .blend file in JSON.

This makes it easy to 'read' the actual content of a .blend, to diff it, etc.

This is still very WIP, right it's OK to get the general structure of the .blend
(all its blocks), but data itself is not yet exportable.

There are also options to filter (based on keys & values regex matching) what is
exported to JSON, but this is not yet fully working as expected.

This is a (still not complete) python module able to read and write a .blend file.

Advanced git commit script: add features to help sorting commits by 'release states' (RC2, RC3, etc.).

Useful, since after RC1 we need to only consider bugs backported to current release branch.

- overly relative includes
- duplicate includes

This script does the same thing as git_log_review_commits.py, but additionally
is able to generate release-notes-ready list of 'accepted' revisions, and even
a whole wikified page of bugfixes.

Note I kept it separated from org version for now, ultimately we may remove org one...

Also quiet false positive warnings with casts and whitespace.