remove encoding of versions into the file system (for now?)

remove encoding of versions into the file system (for now?)

* module/ice-9/boot-9.scm (find-versioned-module): Remove. Still had
  some bugs (e.g. for "." in the path and in finding compiled files),
  did too much computation and statting, and we don't really want to
  promote versioning. Nor do we want to hard-code a particular encoding
  of versions in the file-system. Perhaps the real way to do this is to
  be extensible somehow.
  (try-module-autoload): Just dispatch to primitive-load-path in all cases.

* module/rnrs
* module/rnrs.scm:
* module/rnrs/arithmetic/bitwise.scm:
* module/rnrs/arithmetic/fixnums.scm:
* module/rnrs/arithmetic/flonums.scm:
* module/rnrs/base.scm:
* module/rnrs/conditions.scm:
* module/rnrs/control.scm:
* module/rnrs/enums.scm:
* module/rnrs/eval.scm:
* module/rnrs/exceptions.scm:
* module/rnrs/files.scm:
* module/rnrs/hashtables.scm:
* module/rnrs/io/simple.scm:
* module/rnrs/lists.scm:
* module/rnrs/mutable-pairs.scm:
* module/rnrs/mutable-strings.scm:
* module/rnrs/programs.scm:
* module/rnrs/r5rs.scm:
* module/rnrs/records/inspection.scm:
* module/rnrs/records/procedural.scm:
* module/rnrs/records/syntactic.scm:
* module/rnrs/sorting.scm:
* module/rnrs/syntax-case.scm:
* module/rnrs/unicode.scm: Move these files, eliding the "6/" infix, so
  that they are in the normal (unversioned) module path.