Update install notes to be consistent with introduction of pyproject.toml

Author: absurdfarce

docs/installation.rst

@@ -99,15 +99,9 @@ process can take a long time -- as long as 10 minutes in some environments.
 
 In environments where performance is less important, it may be worth it to
 :ref:`disable Cython as documented below <cython-extensions>`.
-You can also use ``CASS_DRIVER_BUILD_CONCURRENCY`` to increase the number of
-threads used to build the driver and any C extensions:
+You can also use ``build-concurrency`` key in the ``tool.cassandra-driver`` table of pyproject.toml to 
+increase the number of threads used to build the driver and any C extensions.
 
-.. code-block:: bash
-
-    $ # installing from source
-    $ CASS_DRIVER_BUILD_CONCURRENCY=8 python setup.py install
-    $ # installing from pip
-    $ CASS_DRIVER_BUILD_CONCURRENCY=8 pip install cassandra-driver
 
 OSX Installation Error
 ^^^^^^^^^^^^^^^^^^^^^^
@@ -161,9 +155,10 @@ for token-aware routing with the ``Murmur3Partitioner``,
 `libev <http://software.schmorp.de/pkg/libev.html>`_ event loop integration,
 and Cython optimized extensions.
 
-When installing manually through setup.py, you can disable both with
-the ``--no-extensions`` option, or selectively disable them with
-with ``--no-murmur3``, ``--no-libev``, or ``--no-cython``.
+When installing manually these options can be disabled by changing the corresponding
+key in the ``tool.cassandra-driver`` table of pyproject.toml to "false".  Please consult
+the ``build-murmur3-extension``, ``build-libev-extension`` and ``build-cython-extensions``
+keys (respectively) to disable these extensions.
 
 To compile the extensions, ensure that GCC and the Python headers are available.
 
@@ -184,36 +179,12 @@ See :ref:`windows_build` for notes on configuring the build environment on Windo
 Cython-based Extensions
 ~~~~~~~~~~~~~~~~~~~~~~~
 By default, this package uses `Cython <http://cython.org/>`_ to optimize core modules and build custom extensions.
-This is not a hard requirement, but is engaged by default to build extensions offering better performance than the
+This is not a hard requirement, but is enabled by default to build extensions offering better performance than the
 pure Python implementation.
 
-This is a costly build phase, especially in clean environments where the Cython compiler must be built
-This build phase can be avoided using the build switch, or an environment variable::
-
-    python setup.py install --no-cython
-
-Alternatively, an environment variable can be used to switch this option regardless of
-context::
-
-    CASS_DRIVER_NO_CYTHON=1 <your script here>
-    - or, to disable all extensions:
-    CASS_DRIVER_NO_EXTENSIONS=1 <your script here>
-
-This method is required when using pip, which provides no other way of injecting user options in a single command::
-
-    CASS_DRIVER_NO_CYTHON=1 pip install cassandra-driver
-    CASS_DRIVER_NO_CYTHON=1 sudo -E pip install ~/python-driver
-
-The environment variable is the preferred option because it spans all invocations of setup.py, and will
-prevent Cython from being materialized as a setup requirement.
-
-If your sudo configuration does not allow SETENV, you must push the option flag down via pip. However, pip
-applies these options to all dependencies (which break on the custom flag). Therefore, you must first install
-dependencies, then use install-option::
-
-    sudo pip install futures
-    sudo pip install --install-option="--no-cython"
-
+This process does take some time, however, so if you wish to build without generating these extensions using
+Cython you can do so by changing the ``build-cython-extensions`` key in the ``tool.cassandra-driver`` table of pyproject.toml.
+By default this key is set to "true"; simply changing it to "false" will disable all Cython functionality.
 
 Supported Event Loops
 ^^^^^^^^^^^^^^^^^^^^^