Add some versionadded info to new incremental codec docs and fix doco nits.

Doc/lib/libcodecs.tex

@@ -112,6 +112,7 @@ class or factory function.
 
 Raises a \exception{LookupError} in case the encoding cannot be found or the
 codec doesn't support an incremental encoder.
+\versionadded{2.5}
 \end{funcdesc}
 
 \begin{funcdesc}{getincrementaldecoder}{encoding}
@@ -120,6 +121,7 @@ class or factory function.
 
 Raises a \exception{LookupError} in case the encoding cannot be found or the
 codec doesn't support an incremental decoder.
+\versionadded{2.5}
 \end{funcdesc}
 
 \begin{funcdesc}{getreader}{encoding}
@@ -229,12 +231,14 @@ an encoding error occurs.
 Uses an incremental encoder to iteratively encode the input provided by
 \var{iterable}. This function is a generator. \var{errors} (as well as
 any other keyword argument) is passed through to the incremental encoder.
+\versionadded{2.5}
 \end{funcdesc}
 
 \begin{funcdesc}{iterdecode}{iterable, encoding\optional{, errors}}
 Uses an incremental decoder to iteratively decode the input provided by
 \var{iterable}. This function is a generator. \var{errors} (as well as
 any other keyword argument) is passed through to the incremental encoder.
+\versionadded{2.5}
 \end{funcdesc}
 
 The module also provides the following constants which are useful
@@ -355,6 +359,8 @@ encoded/decoded with the stateless encoder/decoder.
 
 \subsubsection{IncrementalEncoder Objects \label{incremental-encoder-objects}}
 
+\versionadded{2.5}
+
 The \class{IncrementalEncoder} class is used for encoding an input in multiple
 steps. It defines the following methods which every incremental encoder must
 define in order to be compatible to the Python codec registry.

Lib/codecs.py

@@ -156,13 +156,13 @@ class Codec:
 
 class IncrementalEncoder(object):
     """
-    A IncrementalEncoder encodes an input in multiple steps. The input can be
+    An IncrementalEncoder encodes an input in multiple steps. The input can be
     passed piece by piece to the encode() method. The IncrementalEncoder remembers
     the state of the Encoding process between calls to encode().
     """
     def __init__(self, errors='strict'):
         """
-        Creates a IncrementalEncoder instance.
+        Creates an IncrementalEncoder instance.
 
         The IncrementalEncoder may use different error handling schemes by
         providing the errors keyword argument. See the module docstring