Update 4.02.0

[ghost]

This update is based on my report here: #907
As well as the Dear ImGui updated code. (nuklear is based on)

1. Improve algorithm for mitre joints on thick lines, preserving correct thickness up to 90 degrees angles (e.g. rectangles). If you have custom rendering using thick lines, they will appear a little thicker now. Thanks to ocornut@github.

2. Fix a drawing bug for stroked and filled rectangles when NK_ANTI_ALIASING_OFF is used.
(We do not use negative values here, as it will basically crop 0.5f on offset.x/offset.y, and it will affect the rendering).

Before the patch:

After the patch:

3. Code cleanup.

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Tell me if you want me to change anything, but I have tested enough and this is only slight improvments so far.

Also I would like to keep #907 open in order to keep updating the status of my problems. (for now)

[ghost]

@dumblob I was not sure if the version should be 4.01.5 or 4.02.0? (based on the last change)

[ghost]

@dumblob, if this is not going to be merged, I will just close and delete my fork.

[dumblob]

Hi @eax0r, I didn't have time to look through all your work. I'm really currently totally out of time. If you followed Nuklear for about a year, you understand what are the concerns etc., so I'll check whether I can give you the permission to merge changes and you could merge your changes. I'll personally get back to Nuklear probably first in 3-5 weeks due to my current personal situation.

Generally I value all your effort and think most of it could be merged, but I wanted to stick with the principle "four eyes see more than two" as is the golden review standard 😉.

[dumblob]

@vurtun I found out I can't add any additional collaborators. I think it's time to start a "Nuklear" GitHub organization to allow existing collaborators add additional collaborators. What do you think?

[dumblob]

Enough of waiting. It's painful to lose all the stars, issues and PRs, but it's the only way how to scale.

Welcome the new organization https://github.com/Immediate-Mode-UI (see also #941 ).

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TODO to finish the transition:

1. do not manually transfer all tickets & PRs, but add a comment to those opened (more than 200 😢) stating:

We've moved to https://github.com/Immediate-Mode-UI/Nuklear . If the issue/wish persists, please

1. create a new issue in the new repository
2. close this original issue/PR

This is the first and last notice. After few months, we'll close this issue and lock discussion.

2. chime in all issue trackers of Nuklear bindings repos listed in Readme.md and create issues asking authors whether they are willing to transfer their repos to the https://github.com/Immediate-Mode-UI organization (they'd become members of the org then)
3. @eax0r, @prust, @vurtun you're all admins, so feel free to invite other collaborators (I've set that by default all new collaborators get admin rights, so don't give these permissions just to everybody 😉)

Volunteers for these todo items? I need to get back to my duties now 😢.