Capture difference that pip doesn't allow for install config details … (pypa#233)

* Capture difference that pip doesn't allow for install config details such as the package index to be supplied per project as it is for easy_install.

* Add definition for 'per project index'.

Author: jaraco

source/glossary.rst

@@ -92,6 +92,13 @@ Glossary
         :term:`package <Distribution Package>` discovery and consumption.
 
 
+    Per Project Index
+
+        A private or other non-canonical :term:`Package Index` indicated by
+        a specific :term:`Project` as the index preferred or required to
+        resolve dependencies of that project.
+
+
     Project
 
         A library, framework, script, plugin, application, or collection of data

source/pip_easy_install.rst

@@ -60,6 +60,9 @@ Here's a breakdown of the important differences between pip and easy_install now
 |Exclude scripts during install|No                                |Yes                            |
 |                              |                                  |                               |
 +------------------------------+----------------------------------+-------------------------------+
+|per project index             |Only in virtualenv                |Yes, via setup.cfg             |
+|                              |                                  |                               |
++------------------------------+----------------------------------+-------------------------------+
 
 ----