Enable test for #3707
remove borrowck workarounds from the containers
minor automatic whitespace fixes
auto merge of #6290 : brson/rust/issue-3707, r=thestinger

This issue has been fixed in passing.
auto merge of #6292 : thestinger/rust/cleanup, r=brson
io: handle fread() errors

When, occasionally, trying to read directory instead of file, `fread()`
returns `EISDIR` error. And, considering, absence of error handling,
`read_whole_stream()` just loops indefinitely.