STYLE: confusing wm32, wm64 aliases (issue #364)

- wm32/wm64 were for changing between -m32, -m64 builds on x86_64
  architectures. This is seldom enough not to warrant a special alias.
  Also ambiguous if these could refer to label sizes.

- Remove wm32,wm64 aliases.
- Add wmInt32, wmInt64 aliases for switching WM_LABEL_SIZE.