Problem:    Timer_create is not available on every Mac system. (Hisashi T
            Fujinaka)
Solution:   Adjust #ifdef.

Problem:    Timer_create is not available on every Mac system. (Hisashi T
            Fujinaka)
Solution:   Adjust #ifdef.

Problem:    Wrong return type for main() in tee.c.
Solution:   Use "int" instead of "void".  Remove unused variable.

Problem:    No test for what 8.1.0052 fixes.
Solution:   Add a test. (closes #10531)

Problem:    Error for a command may go over the end of IObuff.
Solution:   Truncate the message.

Problem:    Coverity warns for dead code.
Solution:   Remove the dead code.

Problem:    C89 requires signal handlers to return void.
Solution:   Drop RETSIGTYPE and hard-code a void return value.

Problem:    Running configure fails.
Solution:   Remove line break.

Problem:    Autoconf 2.71 produces many obsolete warnings.
Solution:   Replace obsolete macros with non-obsolete ones, where the
            functionality does not change. (issue #10528)