Remove overlapping content with okenos-guides

This is the initial commit of the okeanos-helpdesk branch.
The main purpose of this branch is to:
* Move non-technical parts (e.g examples) to the okeanos-guides docs,
  where they can be presented in a more user-oriented way
* Correct minor omissions that okeanos-helpdesk has encountered during
  the testing of the image-creator tool

.gitignore

@@ -2,3 +2,4 @@
 build/
 dist/
 *.egg-info
+docs/_build

docs/usage.rst

@@ -191,87 +191,3 @@ In the *Register* sub-menu the user can provide:
 By choosing the *Extract* menu entry the user can dump the image to the local
 file system and finally, if the user selects *Reset*, the system will ignore
 all changes made so far and will start the image creation process again.
-
-Creating a new image
-====================
-
-Suppose you want to create a new Ubuntu server image. Download the installation
-disk from the Internet:
-
-.. code-block:: console
-
-   $ wget http://ubuntureleases.tsl.gr/12.04.1/ubuntu-12.04.1-server-amd64.iso
-
-Create a 2G sparce file to host the new system:
-
-.. code-block:: console
-
-   $ truncate -s 2G ubuntu_hd.raw
-
-And install the Ubuntu system on this file:
-
-.. code-block:: console
-
-   $ sudo kvm -boot d -drive file=ubuntu_hd.raw,format=raw,cache=none,if=virtio \
-     -cdrom ubuntu-12.04.1-server-amd64.iso
-
-After the installation finishes, become root, activate the virtual environment
-you have installed snf-image-creator in, and use *snf-mkimage* to create and
-upload the image:
-
-.. code-block:: console
-
-   $ sudo -s
-   $ source /path/to/snf-image-env/bin/activate
-   $ snf-mkimage ubuntu_hd.raw
-
-In the first screen you will be asked to choose if you want to run the program
-in *Wizard* or *Expert* mode. Choose *Wizard*.
-
-.. image:: /snapshots/01_wizard.png
-
-Then you will be asked to provide a name, a description, an *~okeanos* account
-and the token corresponding to this account. After that you will be asked to
-confirm the provided data.
-
-.. image:: /snapshots/06_confirm.png
-
-Choosing *YES* will create the image and upload it to your *~okeanos* account.
-
-Some caveats on image creation
-==============================
-
-Para-virtualized drivers
-------------------------
-
-*~Okeanos* uses the *VirtIO* framework. The disk I/O controller and the
-Ethernet cards on the VM instances are para-virtualized and need special
-*VirtIO* drivers. Those drivers are included in the Linux Kernel mainline since
-version 2.6.25 and are shipped with all the popular Linux distributions. The
-problem is that if the driver for the para-virtualized disk I/O controller is
-built as module, it needs to be preloaded using an initial ramdisk, otherwise
-the VM will not be able to boot.
-
-In the image creation demonstration above, we initially installed the Ubuntu
-system on a hard disk (*ubuntu_hd.raw*) that was connected on a
-para-virtualized interface (pay attention to the *if=virtio* option of the kvm
-line). Ubuntu and Debian create a generic initial ramdisk file that contains
-many different modules, including the VirtIO drivers. In many distros this is
-not the case. In Arch Linux for example, the user needs to manually add
-*virtio_blk* and *virtio_pci* drivers in */etc/mkinitcpio.conf* and rebuild the
-initial ramdisk [#f1]_ to make the virtio drivers get preloaded during boot.
-For now, *snf-image-creator* cannot resolve this kind of problems and it's left
-to the user to do it.
-
-Swap partitions
----------------
-
-If you want your image to have a swap partitions, make sure this is the last
-partition on the disk. If snf-image-creator detects a swap partition in the end
-of the input media, it will remove the partition when shrinking and will save
-enough information to be able to recreate it during image deployment. This will
-make the image smaller and will speed up the deployment process.
-
-.. rubric:: Footnotes
-
-.. [#f1] https://wiki.archlinux.org/index.php/KVM#Paravirtualized_guests_.28virtio.29