Update installation instructions in documentation

Based on comments by Jeroen in issue #14.

doc/download.rst

+.. highlight:: none
+
+.. _download:
+
+Downloading Mutalyzer
+=====================
+
+The Mutalyzer source code is `hosted on the LUMC GitLab server
+<https://git.lumc.nl/mutalyzer/mutalyzer>`_. The recommended way to get the
+Mutalyzer source code is by cloning the `Git`_ repository::
+
+    git clone https://git.lumc.nl/mutalyzer/mutalyzer.git
+
+This will give you the current development version. See below for working with
+other versions.
+
+
+Release versions
+----------------
+
+All Mutalyzer releases are tagged. You can run ``git tag`` to list the
+available tags. Use ``git checkout <tag>`` to switch to a certain release. For
+example, to swith to the `2.0.0` release::
+
+    git checkout v2.0.0
+
+Alternatively, you can checkout the `release` branch. This branch always
+points to the latest Mutalyzer release.
+
+
+Archive downloads
+-----------------
+
+If for whatever reason you don't want to use Git, you can download the source
+code directly as a zip archive or tarball. The current development version can
+be found from the `project homepage
+<https://git.lumc.nl/mutalyzer/mutalyzer>`_. Archive downloads for release
+versions can be found on the `tags page
+<https://git.lumc.nl/mutalyzer/mutalyzer/tags>`_.
+
+
+.. _Git: http://git-scm.com/

doc/index.rst

@@ -16,6 +16,7 @@ Information for getting Mutalyzer running on a system.
 .. toctree::
    :maxdepth: 2
 
+   download
    install
    config
    run

doc/install.rst

@@ -100,7 +100,7 @@ covered here.
 Assuming you created and activated a virtual environment for Mutalyzer,
 install all required Python packages::
 
-    $ sudo apt-get install python-dev libmysqlclient-dev
+    $ sudo apt-get install python-dev libmysqlclient-dev libxml2-dev libxslt-dev
     $ pip install -r requirements.txt
 
 Now might be a good time to run the unit tests::

doc/run.rst

@@ -5,6 +5,9 @@
 Running Mutalyzer
 =================
 
+Please make sure Mutalyzer can find its configuration file, as detailed in
+:ref:`config`.
+
 Mutalyzer comes with a number of different interfaces, of which the website is
 perhaps the main one. It can be started using a built-in test server that's
 useful for development and debugging purposes like this::