Make missing @include a warning instead of an error

[Gavin Smith]

I have been in the situation of downloading the sources to a package 
only to look at its Texinfo manual, but finding it hard to build it.  
Texinfo manuals often include generated files such as version.texi that 
are only produced by the package build process (e.g. after running 
"configure", which may take a long time or have other problems).

I wonder if in many cases the manual would be nearly all OK to look at 
if missing @include files only gave an warning, not an error.  With 
Texinfo's own manual, if I comment out the "@include version.texi" line
there are only warnings about undefined flags, but the rest of the 
manual is fine.  I expect that this would be the case for most manuals 
and there is not anything really complicated going on with included 
files.

Does anybody have any comments about my proposal to change missing 
@include files to give only a warning?