🔨 Build boxer-sys with static compilation

The `boxer-sys` library was previously building and linking as a dylib,
but this is posing a challenge for linking the binary into the final
application.

In an effort to correct the issues, this is being changed into a
static binary so that the code is linked directly into the executable.

frameworks/boxer-sys/build.rs

@@ -12,12 +12,12 @@ fn compile_boxer() {
 
   cfg
     .define("CMAKE_INSTALL_LIBDIR", "lib")
-    .define("BUILD_SHARED_LIBS", "1");
+    .define("BUILD_SHARED_LIBS", "0");
 
   let dst = cfg.build();
 
-  println!("cargo:rustc-link-search={}", dst.join("lib").display());
-  println!("cargo:rustc-link-lib=dylib=Boxer");
+  build::rustc_link_search!("native={}", dst.join("lib").display());
+  build::rustc_link_lib!("static=Boxer");
 }
 
 // Generates bindgen bindings for GLFW.