bug#20654: 25.0.50; doc string of `query-replace': Describe interactive behavior first

[Drew Adams]

Describe the command first of all from the point of view of an
interactive user, and only secondarily from the point of view of a Lisp
programmer.

The description starts out correctly, in that vein.  But it does not
describe the use of a prefix arg.  An Emacs user must wade through the
entire description, including specifics about each of the Lisp
parameters, before getting to the info about the prefix arg.  And even
then s?he must read attentively or s?he will miss it.

This StackExchange question, as well as comments and answers provided by
fairly experienced Emacs[Lisp] users, supports the need to fix this:
http://emacs.stackexchange.com/q/12688/105


In GNU Emacs 25.0.50.1 (i686-pc-mingw32)
 of 2014-10-20 on LEG570
Bzr revision: 118168 rgm@gnu.org-20141020195941-icp42t8ttcnud09g
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --enable-checking=yes,glyphs CPPFLAGS=-DGLYPH_DEBUG=1'