Merging CZ19/Pixel into master

[tjclement]

Making a draft PR to look into needed changes

[tjclement]

Huge PR, but the relevant parts for a merge are not too bad. It's intended to get CZ19/Pixel merged back into master, and share the changes made for it. I think for the PR we have to focus on only 3 things (because the others are just python_module changes that don't change anything for other badges):

• sndmixer: this PR includes the changes done for CZ20. It includes some new features like looping and streaming wav and mp3 files, and changes the way it mixes multiple channels (namely, additive mixing instead of normalized mixing. The former is how most audio equipment works)

• framebuffer: some small changes, one of which I don't remember or understand anymore. See the comment I added for it. The other changes are to get it to skip lengthy compilation if it's not enabled in KConfig.

• main.c: we made some changed in startup and ota graphics that are not directly mergeable because they break other badges. Let's look at how this can be made neatly.

@renzenicolai what do you think?

[renzenicolai]

LGTM, strangely enough I think this whole PR can be merged without breaking any of the other badges.

There is a merge conflict that needs to be solved, but after that feel free to hit that merge button :smile:

[lgtm-com[bot]]

This pull request introduces 31 alerts and fixes 18 when merging b88f07969b77f25e4207fda22e2c34c26e35656d into 6e28dbc0d222e1c7ba53ba4a0450cc43581e3d4e - view on LGTM.com

new alerts:

• 12 for Except block handles 'BaseException'
• 7 for Unused import
• 4 for Unused local variable
• 2 for Unnecessary pass
• 2 for First parameter of a method is not named 'self'
• 2 for Testing equality to None
• 1 for Unreachable code
• 1 for Variable defined multiple times

fixed alerts:

• 8 for Unused import
• 3 for Unused local variable
• 3 for Unnecessary delete statement in function
• 2 for Testing equality to None
• 2 for Except block handles 'BaseException'