docs: suggest using pip instead of setup.py develop

docs/contributing.rst

@@ -35,7 +35,7 b' To get started with development::'
         virtualenv ../kallithea-venv
         source ../kallithea-venv/bin/activate
         pip install --upgrade pip setuptools
-        python2 setup.py develop
+        pip install -e .
         paster make-config Kallithea my.ini
         paster setup-db my.ini --user=user --email=[e-mail] --password=password --repos=/tmp
         paster serve my.ini --reload &

docs/installation.rst

@@ -40,7 +40,7 b' repository, follow the instructions belo'
         virtualenv ../kallithea-venv
         source ../kallithea-venv/bin/activate
         pip install --upgrade pip setuptools
-        python2 setup.py develop
+        pip install -e .
         python2 setup.py compile_catalog   # for translation of the UI
 
 You can now proceed to :ref:`setup`.
@@ -96,7 +96,7 b' An additional benefit of virtualenv_ is '
   Alternatively, download a .tar.gz from http://pypi.python.org/pypi/Kallithea,
   extract it and run::
 
-    python2 setup.py install
+    pip install .
 
 - This will install Kallithea together with pylons_ and all other required
   python libraries into the activated virtualenv.

docs/overview.rst

@@ -53,7 +53,7 b' installed.'
   updating it is that you take advantage of the most recent improvements. Using
   it directly from a DVCS also means that it is easy to track local customizations.
 
-  Running ``setup.py develop`` in the source will use pip to install the
+  Running ``pip install -e .`` in the source will use pip to install the
   necessary dependencies in the Python environment and create a
   ``.../site-packages/Kallithea.egg-link`` file there that points at the Kallithea
   source.