testsuite: Tests for #6458. Closes #6458
std/extra: changing XXX to FIXME; cleanup

* Get rid of by-value-self workarounds; it works now
* Remove type annotations, they're not needed anymore
* Move http module to extra
extra: change alloc to take &mut self, as per XXX comment
extra: change XXX to FIXME and elaborate on comments
Testsuite: Test for #7013. Closes #7013
rustc: More helpful error message when using a struct type like a function

Closes #6702
testsuite: Test for #6132

Closes #6132
rustc: Remove FIXME (see #4949)
testsuite: Test for #4447

Closes #4447
testsuite: Un-xfail test for #5917
auto merge of #8570 : catamorphism/rust/2013-08-16-rollup, r=catamorphism

Nothing arguable here, as far as I can tell.