* Split string.ss into string-mzlib.ss which is left in mzlib.ss
* Call the string.ss from scheme (which now has only stuff from scheme/base)
svn: r9196
* Renamed mzlib/contract header (distinguished from the other)
* Added "scheme.ss" to test things from the scheme collection
* Added "for.ss" to the "scheme.ss" tests, renamed the section header
to `for'
* Added "list.ss" to test stuff from scheme/list: flatten
* Moved list tests from "function.ss" to "list.ss": foldl, foldr,
filter, memf, assf, sort; removed bogus quicksort-mergesort test
svn: r8928
