Clean up README.md
Remove trailing whitespace in README.md
Add Arch instructions (merged from GH-35).

Thanks @thiderman!
Change Ubuntu 12.04 to Ubuntu/Debian in README.md

That should work in most versions of Ubuntu and Debian.
Add modeline with tw per @ashleyh's suggestion
Squashed 'third-party/libuv/' content from commit 3c40224

git-subtree-dir: third-party/libuv
git-subtree-split: 3c4022464acd92607f21c6eef69330fb071d0400
Merge commit 'a302c65dc65896776d6cb9e2c89a6ccc77ada530' as 'third-party/libuv'
get-libuv.sh: compile bundled libuv

Rename file to reflect new intent of script. Libuv is bundled into the
third-party directory. Modify the script to compile but not fetch libuv.
Makefile: refer to renamed compile-libuv.sh

get-libuv.sh was renamed to compile-libuv.sh
third-party: add note on role of directory

Add a brief README on the purpose of the third-party directory and some
suggestions for how to manage it. The neovim bigwigs may want to
re-draft the README.
Fix anchors
Fix previous commit
Changed name of binary (vim -> nvim).

Also updated affected config files and test49.vim
README.md: cosmetic fixes
os_unix: add #include for libuv
os_unix: switch to libuv chdir() function
os_unix: use libuv total memory function
move libuv functions to os.c and io.c module

Despite being an io library, the functions currently implemented with
libuv include some non-I/O tasks like getting the total amount of
memory.
Create new OS module

This module will contain all functions that perform OS calls such as IO,
filesystem access, etc.
Add missing include guard to os module