Terminology and typography fixes

Doc/whatsnew/whatsnew20.tex

@@ -777,7 +777,7 @@ fact will break in 2.0.
 
 Some work has been done to make integers and long integers a bit more
 interchangeable.  In 1.5.2, large-file support was added for Solaris,
-to allow reading files larger than 2Gb; this made the \method{tell()}
+to allow reading files larger than 2~GiB; this made the \method{tell()}
 method of file objects return a long integer instead of a regular
 integer.  Some code would subtract two file offsets and attempt to use
 the result to multiply a sequence or slice a string, but this raised a

Doc/whatsnew/whatsnew23.tex

@@ -1479,7 +1479,7 @@ now return enhanced tuples:
 ('amk', 500)
 \end{verbatim}
 
-\item The \module{gzip} module can now handle files exceeding 2~Gb.  
+\item The \module{gzip} module can now handle files exceeding 2~GiB.  
 
 \item The new \module{heapq} module contains an implementation of a
 heap queue algorithm.  A heap is an array-like data structure that

Doc/whatsnew/whatsnew25.tex

@@ -960,7 +960,7 @@ space for a \ctype{PyObject} representing the item.  2147483647*4 is
 already more bytes than a 32-bit address space can contain.
 
 It's possible to address that much memory on a 64-bit platform,
-however.  The pointers for a list that size would only require 16GiB
+however.  The pointers for a list that size would only require 16~GiB
 of space, so it's not unreasonable that Python programmers might
 construct lists that large.  Therefore, the Python interpreter had to
 be changed to use some type other than \ctype{int}, and this will be a
@@ -1723,8 +1723,8 @@ Brandl.)
 % Patch 1120353
 
 \item The \module{zipfile} module now supports the ZIP64 version of the 
-format, meaning that a .zip archive can now be larger than 4 GiB and
-can contain individual files larger than 4 GiB.  (Contributed by
+format, meaning that a .zip archive can now be larger than 4~GiB and
+can contain individual files larger than 4~GiB.  (Contributed by
 Ronald Oussoren.)
 % Patch 1446489