merging extensions/VisualEditor.
to support 'feedback' and other features also merging these changes, which mostly add API and other libraries
to core.
MFT
r105630,
r105646,
r105918,
r105954,
r105963,
r105970,
r105974,
r106003,
r106059
and extensions/UploadWizard, since libraries were moved from there into core, and we can't register libs twice.