removed homebrew, simplified with packages for git and node
Update INSTALL_OSX.md

Changed minimum node version requirement to 0.8 as per PR comments
Update INSTALL_OSX.md

Added minimum version 0.10.4 as it is now the min req. Newer modules are now in use, necessitating 0.10.4
Update INSTALL_OSX.md

added newline fix
Include Arch Linux install instructions, other refinements.

A global install of coffee-script is probably not needed.

I have had issues before with a https_proxy envvar being set.
Cannot reproduce, but including just in case.

Line-wraps at 80 symbols.
Merge pull request #46 from veox/master

Include Arch Linux install instructions, other small improvements
Merge pull request #30 from aantonop/docs/osx

removed homebrew, simplified with packages for git and node