Added version annotations, remove hard tabs.

Doc/api/abstract.tex

@@ -868,7 +868,7 @@ else {
     /* continue doing useful work */
 }
 
-\section{Buffer Protocol \label{buffer}}
+\section{Buffer Protocol \label{abstract-buffer}}
 
 \begin{cfuncdesc}{int}{PyObject_AsCharBuffer}{PyObject *obj,
                                               const char **buffer,
@@ -878,6 +878,7 @@ else {
   character buffer interface.  On success, returns \code{1}, sets
   \var{buffer} to the memory location and \var{buffer} to the buffer
   length.  Returns \code{0} and sets a \exception{TypeError} on error.
+  \versionadded{1.6}
 \end{cfuncdesc}
 
 \begin{cfuncdesc}{int}{PyObject_AsReadBuffer}{PyObject *obj,
@@ -889,11 +890,13 @@ else {
   \code{1}, sets \var{buffer} to the memory location and \var{buffer}
   to the buffer length.  Returns \code{0} and sets a
   \exception{TypeError} on error.
+  \versionadded{1.6}
 \end{cfuncdesc}
 
 \begin{cfuncdesc}{int}{PyObject_CheckReadBuffer}{PyObject *o}
   Returns \code{1} if \var{o} supports the single-segment readable
   buffer interface.  Otherwise returns \code{0}.
+  \versionadded{2.2}
 \enc{cfuncdesc}
 
 \begin{cfuncdesc}{int}{PyObject_AsWriteBuffer}{PyObject *obj,
@@ -904,6 +907,7 @@ else {
   interface.  On success, returns \code{1}, sets \var{buffer} to the
   memory location and \var{buffer} to the buffer length.  Returns
   \code{0} and sets a \exception{TypeError} on error.
+  \versionadded{1.6}
 \end{cfuncdesc}
 
 \end{verbatim}