This is a big API change, and it's probably not in it's ideal
shape right now. Physis makes a big assumption that the pool of
game data that you're reading from is in the compressed, SqPack
format like in retail. However, as the projects that use Physis
expand - so does the scope of data people want to punt into it.
For example, we have Icarus that makes it easy to read Excel data
but it can only do so through SqPack which makes it less useful in
scenarios where you want to read unpacked Excel modded files or
perhaps Excel data from the network.
So I created a Resource trait that GameData now implements (and
it's now called SqPackResource.) In a similar vain, Physis comes
with an UnpackedResource and a ResourceResolver to chain multiple
Resources together.
This simplifes the handling of "new installs" in applications like
Astra, who may end up calling GameData::apply_patch on an "invalid"
GameData struct. We should allow applications to still hold onto these
so it keeps track of game_directory.
We had a few odd dependencies that caused nothing but pain in dependent projects
like libphysis. One of these was libunshield (a C library) that our game_install
feature used, but to be honest this was the wrong library to put this code. It
was really only ever used by Astra, and should live there instead - there's no
reason to have it shared between applications (and it's small enough to be
copied if *you* need it.) Also that also killed the system-deps dependency which
had a significant impact on our build time.
Another dependency was replaced: libz-sys. This is replaced by the pure Rust
libz-rs (through libz-rs-sys) which should simplify deploying physis without
having to worry about manually linking libz or other nonsense. Some leftover
copied code from flate2 can also be removed.
I also removed the visual_data feature as Astra ended up using it anyway, and
the distinction doesn't make much sense now. It was previously to gate some
dependencies needed for visual data extraction, but the bitflags and half crates
are small. I can look into splitting the crate up into more features if needed
later.
A dependency that was erroneously included in the refactoring was quote, which
has been removed. Also ran cargo fmt, clippy too.
