ZSH compat update on crosscompile.bash

Zsh doesn't split strings on blanks like bash with $IFS set to `$' \n\t'`. 
`shwordsplit` is a workaround which doesn't require to convert your long "bash-iterable" strings to arrays.
Merge pull request #10 from jeromenerf/patch-1

ZSH compat update on crosscompile.bash