Adding experimental support for OSX Mavericks via "Install OS X Mavericks.app"

Just like #770, this one is semi-working... it produces an InstallESD.dmg output for OSX Mavericks, but VMWare Fusion refuses to boot from the disk...

There must be something that changed between Mountain Lion and Mavericks, but it's not immediately apparent to me, as I don't think I fully understand how the UEFI boot process determines whether a boot disk is bootable...

I'm getting a very similar problem to what I was seeing in VirtualBox for #770

![screenshot 2013-11-08 15 19 27](https://f.cloud.github.com/assets/122524/1504746/094652bc-48c4-11e3-914b-3e4e240bd6cf.png)

@timsutton :  Do you have any insights here?

can you change it to `sed -i'' -e ...`  - it is more portable