AutoConf web documentation bug.

[Mostafa]

In 
http://www.gnu.org/software/autoconf/manual/autoconf.html#Conditional-constructs
 , under the definition for m4_ifval, I believe the following clause is 
erroneous:

This is shorthand for:

          m4_if([cond], [], [if-true], [if-false])

Since the latter expands to if-true if cond is empty, while the definition for 
m4_ifval says m4_ifval([cond], [if-true], [if-false]) expands to if-true if 
cond is NOT empty.

This was rather confusing and I had to verify the correct behaviour via a 
configure.ac template.

Hope this is corrected.

Thanks,

Mostafa