#1 gchistory breaks independent readline library

[Dr. Werner Fink]

The gchistory patch the files isearch.c, misc.c, and
search.c from the readline library to include the
unwind_prot.h header file of the bash. This is IMHO
a bug because it makes it impossible to use bash with
an external readline library and also makes it
impossible to build a standalone readline library
used not only by the bash.

Werner