rt: don't save and restore xmm/regs in __morestack.
field renaming
commenting parser
change to parsing using tts

also, updates test cases a bit
Improve documentation for core::io.
Improve docs for Core::ReaderUtil.

I filled out better descriptions for all of the neccesary
functions.
Typo fix. u8 -> i8
Removed mut-fields from Mut, removed borrow_const from Mut
Removed all uses of Mut from workcache, replaced with @mut
Removed libcore/mutable.rs, Mut<T> is now dead.
auto merge of #5678 : Thiez/rust/no-Mut, r=thestinger

This pull request completely removes Mut<T> and the associated file (libcore/mutable.rs). Some minor changes were made to workcache (libstd/workcache.rs) as it was using Mut.

r?
install the librust{doc,pkg} host libraries
remove trailing whitespace
Remove excess trailing whitespace.
libstd: implement fileinput.

Iterate over lines in a series of files. API (mostly) adopted from
Python's fileinput module.
libstd: implement io::Reader for fileinput.
auto merge of #5685 : thestinger/rust/build, r=graydon
libstd: make fileinput tests pass.
auto merge of #5673 : steveklabnik/rust/improve_io_docs, r=catamorphism

When I submitted #5659, it apparently caused some test failures. Then, because I left it in my incoming rather than making a new branch, I deleted my commit.

Let's try this again, this time, with its own branch so that I don't screw it up.

r?
auto merge of #5674 : steveklabnik/rust/improve_reader_util_docs, r=catamorphism

I filled out better descriptions for all of the necessary
functions.

r?