This addition triggered several other changes:
* -k for a Mac OS X embedding is now relative to the __PLTSCHEME
segment (which means that executables won't break if you strip
them, for example)
* the command-line no longer has a limited size for Mac OS X
launchers and embedding executables
* Mac OS X GUI and Windows launchers record the creation-time
collection path, unless they are created as "relative" launchers
--- a reversal of opinion from my earlier commit; the problem
with syntactic simplification is that it may not refer to the
same file, due to soft links; given that true normalization is
impossible, simplify-path and simple-form-path provide a good
compromise between preserving paths as given and exanding
soft links as neede
