message: [doc] Remove outdated Gitian build guide
diff: -### Gavin's notes on getting gitian builds up and running using KVM
  -
  -These instructions distilled from
  -[https://help.ubuntu.com/community/KVM/Installation](https://help.ubuntu.com/community/KVM/Installation).
  -
  -You need the right hardware: you need a 64-bit-capable CPU with hardware virtualization support (Intel VT-x or AMD-V). Not all modern CPUs support hardware virtualization.
  -
  -You probably need to enable hardware virtualization in your machine's BIOS.
  -
  -You need to be running a recent version of 64-bit-Ubuntu, and you need to install several prerequisites:
  -
  - sudo apt-get install ruby apache2 git apt-cacher-ng python-vm-builder qemu-kvm
  -
  -Sanity checks:
  -
  - sudo service apt-cacher-ng status # Should return apt-cacher-ng is running
  - ls -l /dev/kvm # Should show a /dev/kvm device
  -
  -
  -Once you've got the right hardware and software:
  -
  - git clone git://github.com/bitcoin/bitcoin.git
  - git clone git://github.com/devrandom/gitian-builder.git
  - mkdir gitian-builder/inputs
  - cd gitian-builder/inputs
  -
  - # Create base images
  - cd gitian-builder
  - bin/make-base-vm --suite trusty --arch amd64
  - cd ..
  -
  - # Get inputs (see doc/release-process.md for exact inputs needed and where to get them)
  - ...
  -
  - # For further build instructions see doc/release-process.md
  - ...
  -
  ----------------------
  -
  -`gitian-builder` now also supports building using LXC. See
  -[help.ubuntu.com](https://help.ubuntu.com/14.04/serverguide/lxc.html)
  -for how to get LXC up and running under Ubuntu.
  -
  -If your main machine is a 64-bit Mac or PC with a few gigabytes of memory
  -and at least 10 gigabytes of free disk space, you can `gitian-build` using
  -LXC running inside a virtual machine.
  -
  -Here's a description of Gavin's setup on OSX 10.6:
  -
  -1. Download and install VirtualBox from [https://www.virtualbox.org/](https://www.virtualbox.org/)
  -
  -2. Download the 64-bit Ubuntu Desktop 12.04 LTS .iso CD image from
  - [http://www.ubuntu.com/](http://www.ubuntu.com/)
  -
  -3. Run VirtualBox and create a new virtual machine, using the Ubuntu .iso (see the [VirtualBox documentation](https://www.virtualbox.org/wiki/Documentation) for details). Create it with at least 2 gigabytes of memory and a disk that is at least 20 gigabytes big.
  -
  -4. Inside the running Ubuntu desktop, install:
  -
  - sudo apt-get install debootstrap lxc ruby apache2 git apt-cacher-ng python-vm-builder
  -
  -5. Still inside Ubuntu, tell gitian-builder to use LXC, then follow the "Once you've got the right hardware and software" instructions above:
  -
  - export USE_LXC=1
  - git clone git://github.com/bitcoin/bitcoin.git
  - ... etc
  +How to do a gitian build is documented in [Gitian Build](/doc/gitian-building-bu.md)
  