Removed waf script debugging output.

The waf build scripts for bde had debugging info to help determine
what the third party support was doing.
Improve wscript for third party packages

- Use python builtin function to determine the endianness of the
  machine.

- Improve the handling of cflags passed from BDE's wscript.

- Make the wscript usable dependently. This makes relocating the third
  party directories into separate repos easier.

Discovered some problems that will require further work and
investigation:

- The bdl.pc now depends on the third party libraries
  by name. This means that .pc files should be generated for the third
  party libraries as well, which currently is not the case.

- The library name for decNumber is decNumber (note the capital N). I
  don't think we want to start to use uppercase letter names for libraries,
  given that no existing library names contain uppercase letters.