note whitespace rules, explain setup.py dev

Author: mcdonc

HACKING.txt

@@ -30,11 +30,13 @@ checkout.
   $ env/bin/easy_install setuptools-git
 
 - Install Pyramid from the checkout into the virtualenv using ``setup.py
-  develop`` (running ``setup.py develop`` *must* be done while the current
-  working directory is the ``pyramid`` checkout directory)::
+  dev``.  ``setup.py dev`` is an alias for "setup.py develop" which also
+  installs testing requirements such as nose and coverage.  Running
+  ``setup.py dev`` *must* be done while the current working directory is the
+  ``pyramid`` checkout directory::
 
   $ cd pyramid
-  $ ../env/bin/python setup.py develop
+  $ ../env/bin/python setup.py dev
 
 - At that point, you should be able to create new Pyramid projects by using
   ``pcreate``::
@@ -85,6 +87,9 @@ Coding Style
   2 newlines between classes.  But 80-column lines, in particular, are
   mandatory.
 
+- Please do not remove trailing whitespace.  Configure your editor to reduce
+  diff noise.
+
 Running Tests
 --------------
 
@@ -110,8 +115,8 @@ Test Coverage
 
 - The codebase *must* have 100% test statement coverage after each commit.
   You can test coverage via ``tox -e coverage``, or alternately by installing
-  ``nose`` and ``coverage`` into your virtualenv, and running ``setup.py
-  nosetests --with-coverage``.
+  ``nose`` and ``coverage`` into your virtualenv (easiest via ``setup.py
+  dev``) , and running ``setup.py nosetests --with-coverage``.
 
 Documentation Coverage and Building HTML Documentation
 ------------------------------------------------------