Expose Subversion revision number (calculated via "svnversion .") to Python.
Add C API function Py_GetBuildNumber(), add it to the interactive prompt
banner (i.e. Py_GetBuildInfo()), and add it as the sys.build_number
attribute. The build number is a string instead of an int because it may
contain a trailing 'M' if there are local modifications.
diff --git a/Doc/api/init.tex b/Doc/api/init.tex
index 51b925f..67f74a1 100644
--- a/Doc/api/init.tex
+++ b/Doc/api/init.tex
@@ -272,6 +272,12 @@
\withsubitem{(in module sys)}{\ttindex{version}}
\end{cfuncdesc}
+\begin{cfuncdesc}{const char*}{Py_GetBuildNumber}{}
+ Return a string representing the Subversion revision that this Python
+ executable was built from. This number is a string because it may contain a
+ trailing 'M' if Python was built from a mixed revision source tree.
+\end{cfuncdesc}
+
\begin{cfuncdesc}{const char*}{Py_GetPlatform}{}
Return the platform identifier for the current platform. On \UNIX,
this is formed from the ``official'' name of the operating system,
diff --git a/Doc/lib/libsys.tex b/Doc/lib/libsys.tex
index 4efe5f6..7ffa35d 100644
--- a/Doc/lib/libsys.tex
+++ b/Doc/lib/libsys.tex
@@ -27,6 +27,12 @@
\versionadded{2.0}
\end{datadesc}
+\begin{datadesc}{build_number}
+ A string representing the Subversion revision that this Python executable
+ was built from. This number is a string because it may contain a trailing
+ 'M' if Python was built from a mixed revision source tree.
+\end{datadesc}
+
\begin{datadesc}{builtin_module_names}
A tuple of strings giving the names of all modules that are compiled
into this Python interpreter. (This information is not available in