Remove the `swf_version` parameter from `Activation` constructors,
because this was incorrectly using the global or root SWF version
most times.
Instead, grab the SWF version for the activation directly from the
base clip.
* #[derive(Collect)] should be before #[collect]
* Replace redunant `&buf[..]` with `buf`
* Changes most cases of UPPERCase to UpperCase
* Allow upper_case_acronym on most SWF types, as they are from
SWF spec/more annoying to change.