[doc] Add extra_require section for setup.py; Update distros names

doc/source/installation.rst

@@ -73,8 +73,8 @@ As you will see, **most of the packages are required only by the Cadbiom GUI**,
 whose installation is optional for simplification purposes.
 
 
-Debian-like systems (Ubuntu)
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Debian-like systems (Debian/Ubuntu/Mint)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 - python2.7-dev
 - libxml2-dev
@@ -91,8 +91,8 @@ You can install these dependencies with the following shell command::
   $ sudo apt-get install python-gtksourceview2 python2.7-dev libxml2-dev libxslt1-dev \
   libxslt1-dev libgraphviz-dev pkg-config python-glade2 python-gtk2 python-tk
 
-Red Hat-like systems (Fedora/CentOS)
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Red Hat-like systems (RHEL/Fedora/CentOS)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 - python-devel
 - libxml-devel
@@ -219,6 +219,9 @@ The ``make dev_install`` command uses ``pip install -e .[dev]`` command which al
 you to follow the development branch as it changes by creating links in the right places
 and installing the command line scripts to the appropriate locations.
 
+Moreover, it installs packages listed in the dev section of ``extras_require`` in
+``setup.py/setup.cfg``, in addition to any normal cadbiom dependencies as necessary.
+
 Please note that your changes in the code are directly usable without having to reinstall the packages.
 
 Then, if you want to update Cadbiom at any time, in the same directory do: