Distinguish tuple elements by index in mem_categorization. Fixes #5362.
replace old_iter::repeat with the Times trait
Adapt the getter macro to implement Clone, Eq and Ord for n-ary tuples
Use match instead of intermediate variable
Replace Tuple{2..12} trait with CloneableTuple{2..12} and ImmutableTuple{2..12}

Make n{0..11} methods return cloned values, and create n{0..12}_ref methods for returning references
Fix Ord implementation to use lexical ordering
Move tuple tests into submodule
minor automated whitespace fixes
Add Ptr::to_option method
auto merge of #6603 : thestinger/rust/whitespace, r=thestinger
Correct tuple Ord impl, add Total{Eq,Ord} impls and add some tests.
auto merge of #6595 : bjz/rust/core-tuple, r=thestinger
Use assert_eq! rather than assert! where possible
auto merge of #6601 : cmr/rust/assert_eq, r=Aatch
auto merge of #6106 : thestinger/rust/iter, r=bstrie

I don't have a strong opinion on the function vs. method, but there's no point in having both. I'd like to make a `repeat` adaptor like Python/Haskell for turning a value into an infinite stream of the value, so this has to at least be renamed.
Add additional documentation in core::io.

Added docs for stdout, stderr, print, and println.
Add docs for stdin in core::io.
Added note about prelude inclusion.
Elaborate a bit in the Reader docs regarding stream position.

Had a conversation with @cmr in IRC about some places that these
docs were confusing. The functions that advance the stream now say so.

In addition, I think that calling out the similarities to familliar C
functions should help people coming from other languages.
auto merge of #6620 : steveklabnik/rust/stdin_docs, r=brson