Replace ad-hoc build system with a single Makefile

[glebm]

Advantages:

• Ubiquitous.
• Battle-tested.
• Only rebuilds when necessary.
• Can build in parallel (make -j4 dist).
• Well-known.

Disadvantages:

• Somewhat obscure syntax (though many know it).
• File-based:
  • Phony targets that are prerequisites to other targets cannot have the same name as a file.
  • The need to rebuild decisions are taken based on file mtimes only, not the contents.

[glebm]

By the way, for seeing tabs and spaces on GitHub, you can use this: https://github.com/glebm/render-whitespace-on-github

[orlandohill]

Thanks! Good idea to switch to Make.