[build] Add build knowledge of dynamic libraries

Bonnibel will now build dynamic libraries when they're dependencies for
non-statically linked modules. It will also copy those shared libraries
into the initrd image for programs being copied into the image.

src/libraries/bootproto/bootproto.module

@@ -1,7 +1,7 @@
 # vim: ft=python
 
 bp = module("bootproto",
-    kind = "lib",
+    kind = "headers",
     public_headers = [
         "bootproto/acpi.h",
         "bootproto/bootconfig.h",