Updated dependencies and added one liner for install on OSX

Readme.md

@@ -18,6 +18,12 @@
 
 Unless previously installed you'll _need_ __Cairo__. For system-specific installation view the [Wiki](https://github.com/LearnBoost/node-canvas/wiki/_pages).
 
+You can quickly install Cairo and its dependencies for OS X using the one liner below:
+
+```bash
+wget https://raw.githubusercontent.com/LearnBoost/node-canvas/master/install -O - | sh
+```
+
 ## Screencasts
 
   - [Introduction](http://screenr.com/CTk)

install

@@ -1,10 +1,10 @@
 #!/bin/sh
 
-PKG_CONFIG="http://pkgconfig.freedesktop.org/releases/pkg-config-0.23.tar.gz"
-PIXMAN="http://www.cairographics.org/releases/pixman-0.28.0.tar.gz"
-CAIRO="http://cairographics.org/releases/cairo-1.12.8.tar.xz"
+PKG_CONFIG="http://pkgconfig.freedesktop.org/releases/pkg-config-0.28.tar.gz"
+PIXMAN="http://www.cairographics.org/releases/pixman-0.32.4.tar.gz"
+CAIRO="http://cairographics.org/releases/cairo-1.12.16.tar.xz"
 FREETYPE="http://download.savannah.gnu.org/releases/freetype/freetype-2.4.10.tar.gz"
-LIBPNG="ftp://ftp.simplesystems.org/pub/libpng/png/src/libpng-1.5.13.tar.gz"
+LIBPNG="http://downloads.sourceforge.net/project/libpng/libpng16/1.6.10/libpng-1.6.10.tar.gz"
 PREFIX=${1-/usr/local}
 
 require() {