Added:

- Incremental builds (object caching by mtime)
- `build.kind` with `staticlib` support
- Custom output directory via `build.target`

src/core/builder/mod.rs

@@ -9,6 +9,7 @@ pub struct BuildContext<'a> {
     pub language: &'a str,
     pub standard: &'a str,
     pub target_dir: Option<&'a str>,
+    pub kind: &'a str,
     pub include_dirs: &'a [String],
     pub lib_dirs: &'a [String],
     pub libs: &'a [String],