bug#11851: 24.1.50; info.el: show messages only when interactive

[Drew Adams]

In several places in info.el there is a function that could be used in a
non-interactive context (e.g. by 3rd-party code).  And in such a context
it might sometimes not be appropriate to display the various messages
that are currently shown unconditionally.
 
Please add optional MSGP arguments and conditionalize the calls to
`message' using `called-interactively'.  Thx.
 
The only alternative for 3rd-party code that wants to reuse such
functions is to redefine them to add optional MSGP args etc.  Better
that Emacs should do that from the outset.
 

In GNU Emacs 24.1.50.1 (i386-mingw-nt5.1.2600)
 of 2012-07-01 on MARVIN
Bzr revision: 108826 yamaoka@jpl.org-20120702004841-kzatmydft6dct0ry
Windowing system distributor `Microsoft Corp.', version 5.1.2600
Configured using:
 `configure --with-gcc (4.6) --no-opt --enable-checking --cflags
 -ID:/devel/emacs/libs/libXpm-3.5.8/include
 -ID:/devel/emacs/libs/libXpm-3.5.8/src
 -ID:/devel/emacs/libs/libpng-dev_1.4.3-1/include
 -ID:/devel/emacs/libs/zlib-dev_1.2.5-2/include
 -ID:/devel/emacs/libs/giflib-4.1.4-1/include
 -ID:/devel/emacs/libs/jpeg-6b-4/include
 -ID:/devel/emacs/libs/tiff-3.8.2-1/include
 -ID:/devel/emacs/libs/gnutls-3.0.9/include
 -ID:/devel/emacs/libs/libiconv-1.13.1-1-dev/include
 -ID:/devel/emacs/libs/libxml2-2.7.8/include/libxml2'