Sandbox makefile: bootstrap included in main makefile again.
Sandbox makefile: curl now runs make install instead of just make to install.
Sandbox makefile: Bashed noisy trace.
Sandbox makefile: cosmetic whitespace change.
Sandbox makefile: XZ no longer unexplicably uses a .xz archive.
Sandbox makefile: Fixed ZLIB url.
Sandbox makefile: Added ZLIB to list of bootstrap packages.
Sandbox makefile: Updated bootstrap deps on tar.