Revert "Errors with the same span print the span once"

This reverts commit 6030e3982a52c8d9ede225f992088bb75fba4ef1.
docs: Sketch out rustpkg manual
rustpkg: In doc, mention other implicit RUST_PATH entries

as per Graydon's comment
test: fix for missing ARM support
Remove a stray new operator in rust_task.h
auto merge of #6015 : catamorphism/rust/rustpkg-doc-second-try, r=catamorphism

r? @graydon

Only change from the version that you read is that I addressed your comment about `RUST_PATH`.
Use backticks for the unsafe keyword in error messages
auto merge of #6017 : brson/rust/revert-span-merge, r=catamorphism

This reverts commit 6030e3982a52c8d9ede225f992088bb75fba4ef1.

This reorders error messages in ways that aren't intended. A more satisfying solution will require an interface that allows diagnostics to be grouped together, so that messages that logically belong together aren't reordered.

#4569
auto merge of #6020 : yichoi/rust/pull-0423, r=brson

fix for missing ARM support to pass make stage of rpass
auto merge of #6025 : alexcrichton/rust/issue-2697, r=catamorphism

Closes #2697

I guess all of the uses weren't around any more, because everything continued to compile (at least on OSX). If bors doesn't like it for another platform I can try to track it down as well.
Attempt to fix x86 only strconv test failure
auto merge of #6026 : isanbard/rust/ca73fbf72615575f106ee18160580711aca89d85, r=catamorphism

When the number of parameters is 1, then 'parameter' should remain singular.
Otherwise pluralize it.
auto merge of #6027 : alexcrichton/rust/more-backticks, r=catamorphism

It seems that the general convention of error messages is to have keywords in backticks, so it's probably a good idea to keep doing that.
core, rustc: Warning police
rustc: Comments only: change XXX to FIXME
rustc: Remove dead code
auto merge of #6022 : catamorphism/rust/warning-police, r=catamorphism
inline the primitive numeric operations
auto merge of #6028 : Kimundi/rust/strconv-test-fixup, r=brson

r? @brson 

Can't test atm, but it probably failed because of 32bit float precision loss of the float literal.
auto merge of #6034 : thestinger/rust/num, r=catamorphism,pcwalton