- use -name test before -type test to avoid calling stat(2) on every file.
- use -delete instead of -exec rm to avoid forking

- reduces unexpected interactions between various make elements

- also add some comments about the side-effects

The Makefiles are now in the makefiles sub-directory

The "-f | -force" option in wmakeLnInclude is now "-u | -update" for
consistency with the other scripts.

The "Usage" entry in the headers is now consistently formatted in all
scripts.

wcleanPlatform is a more general and cleaner version of wcleanMachine
supporting the "-all" option to provide the equivalent of wcleanAll.

Both wcleanMachine and wcleanAll are now deprecated and will be removed
for the next major release.