* Lookup mingw problems with autoconf.

  From Aaron Schweiger:

   As a work-around I modified the configure script, line 1135 so,

    cat conftest.$ac_ext >&5
    rm -rf conftest*
    CPP=cpp                              // CHANGED /lib/cpp -> cpp
    fi
    rm -f conftest*
    fi

   ...

   What I did was change all /tmp/conftestval to:

    __TMPFILE=conftestval

   That allowed configure to run cleanly.


* Keep entries in a list as well as in the hash table for faster
  iteration.

  Is this nessessary? Maybe not since the current behavior causes the
  table to iterate (comparatively) slow when there are few entries and
  many buckets. This causes the iteration to be about as slow with many
  entries as with few.

  See below for a list structure.

* Remove the list-pointers from the hash entry structure and instead
  use a list_t which contains the hash entries. Like:

  typedef struct s_l
  {
     struct s_l *p_next;
     struct s_l *p_prev;
     void *p_data;
  } ght_list_t;

  and point the p_data to the hash entries.