Added development guide and installer2iso script.

DEVELOPMENT.md outlines the process for creating a Yosemite VM. (partial)
The installer2iso.sh script converts a Yosemite installer, from the App Store,
to an iso for use as a boot CD with VirtualBox.
This is in partial fufillment of #3
Moved brew and cask installs to separate scripts.

Following in the steps of mathiasbynens/dotfiles we separate out application
specific tasks.
bootstrap.sh should be modified to call brew.sh and cask.sh
Removed brew cask installs from brew.sh

These cask installs were moved to cask.sh in previous commit:
SHA: effed653bfb0e134df287bf1922d8a345f2d178e
Changed to executable bash scripts

Updated bootstrap.sh to call bash
Removed comment about Xcode TOS

Xcode is not actually installed.
Things proceed correctly anyways.
Removed MacTex references

We should reintroduce this when it is easy to enable/disable various parts of
the entire setup process.
See issue #2
Added calls to brew.sh and cask.sh from bootstrap.sh
Changed installer2iso to complete VM builder.

create-OSX-VM.sh now converts an Installer app into an ISO, and then builds a
VirtualBox VM with 2GiB RAM, and 20GiB HDD.
The script depends on iesd and VirtualBox of course.
The VM will launch after successful creation.
Modified instructions to work with create-OSX-VM
Moved development guide and updated README
Ignore vim swap files.