This allows handling path conversions in a more structured way,
as well as avoiding needless UTF-8 checks. All argument inputs
use `Utf8NativePathBuf`, while all config entries use
`Utf8UnixPathBuf`, ensuring that we deserialize/serialize using
forward slashes. We can omit `.display()` and lossy UTF-8
conversions since all paths are known valid UTF-8.
Adds an "extract" list to project configuration:
```
extract:
- symbol: SomeData
binary: Lib/SomeData.bin
header: Lib/SomeData.inc
```
This example extracts the data of symbol
`SomeData` to `out_dir/bin/Lib/SomeData.bin`,
and a C array representation to
`out_dir/include/Lib/SomeData.inc`.
Resolves#11
- Avoid overwriting `symbols.txt` or `splits.txt` if the file was modified since it was read or if the file's contents didn't change.
- Remove `binrw` and `byteorder` dependencies, moving to `FromReader`/`ToWriter` traits.
- Migrate generic bounds to `where` clauses.
- Remove unused `build.rs` logic.
