Fixes spelling errors

[Shrinks99]

• [x] I've followed the contributing guidelines to the best of my understanding
• [x] I've read and understood the contributing guidelines
• [x] I've formatted my code according to Natron's code style (hope so!)
• [x] I've searched the pull requests tracker to ensure that this PR is not a duplicate

PR Description

What type of PR is this?

• [x] Bug fix (non-breaking change which fixes an issue)
• [x] My change requires a change to the documentation
  • [x] I have updated the documentation accordingly

What does this pull request do?

Fixes spelling errors flagged in #759 This also updates CHANGELOG.md retroactively, I did that as a separate commit so it's easier to revert if need be but IMO should be kept in.

Have you tested your changes (if applicable)? If so, how?

NA (I hope... This type of change is pretty minor and I am confident that it won't result in anything bad)

Futher details of this pull request

These spelling fixes do not change anything in /libs, @alexmyczko you may still find that errors come up, but hopefully all the issues within Natron's actual code are resolved!

There are some text editor white space removals. Annoying to review but probably for the best? :\

I probably shouldn't have fixed errors in tools/MINGW-packages/mingw-w64-zlib/06-add-64bit-functions-and-fix-typos.patch... can revert that. Fixed in 5b09f75

[rodlie]

I probably shouldn't have fixed errors in tools/MINGW-packages/mingw-w64-zlib/06-add-64bit-functions-and-fix-typos.patch... can revert that.

Yeah, do not modify patches.

[Shrinks99]

Yeah, do not modify patches.

Reverted.