[Bug-tar] CHAR_BIT undefined in lib/strerror.c (tar-1.19)

[Daniel Villeneuve]

I've had a problem compiling lib/strerror.c in tar-1.19 on solaris2.8, 
because the two #included headers at the start of the file do not define 
CHAR_BIT on that platform.

I've added #include <limits.h> to fix the problem. This should not 
create problems on other platforms, since this header is part of ISO C.
--
Daniel Villeneuve
Kronos, AD OPT Division