+ correct cross-compiling configure check for CF_MKSTEMP macro, by
adding a check cache variable set by AC_CHECK_FUNC (report by
Pierre Labastie).
+ simplify include-dependencies of make_hash and make_keys, to reduce
the need for setting BUILD_CPPFLAGS in cross-compiling when the
build- and target-machines differ.
+ repair broken-linker configuration by restoring a definition of SP
variable to curses.priv.h, and adjusting for cases where sp-funcs
are used.
+ improve configure macro CF_AR_FLAGS, allowing ARFLAGS environment
variable to override (prompted by report by Pablo Cazallas).
