Changed interface for my_strntod() to make it more general and more portable

BUILD/compile-solaris-sparc-purify:
  Cleanup (Changes from Kent)
include/m_string.h:
  New interface for my_strtod()
mysql-test/mysql-test-run.sh:
  Added option --use-old-data to allow one to run a test case on an existing table
  (Good for debugging)
mysql-test/r/strict.result:
  Updated results
mysql-test/r/type_float.result:
  More tests
mysql-test/t/strict.test:
  Safety fix
mysql-test/t/type_float.test:
  More tests
mysys/mf_iocache.c:
  Change flush_io_cache() to my_b_flush_io_cache()
  More debugging
mysys/thr_lock.c:
  Added comment
sql/field.cc:
  Use new my_strntod()
sql/filesort.cc:
  Indentation fixes
sql/item.cc:
  Use new my_strntod()
sql/item_strfunc.cc:
  Use new my_strntod()
sql/item_sum.cc:
  Use new my_strntod()
strings/ctype-cp932.c:
  strnncollsp was missing one argument
strings/ctype-simple.c:
  Use new my_strntod()
strings/ctype-ucs2.c:
  Use new my_strntod()
strings/strtod.c:
  Changed interface:
  - Force user to supply pointer to end of string (eliminates the need for an end \0)
  - More strict error checking (depend less off if INF is set), which makes this more portable
  - Better handling of numbers of type 0.000000....E+...
  - Return pointer to + in case of '+.'
  
  The above should fix a that strict.test failed on Solaris-sparc.

sql/filesort.cc

@@ -567,10 +567,10 @@ write_keys(SORTPARAM *param, register uchar **sort_keys, uint count,
   if (!my_b_inited(tempfile) &&
       open_cached_file(tempfile, mysql_tmpdir, TEMP_PREFIX, DISK_BUFFER_SIZE,
                        MYF(MY_WME)))
-    goto err;                                        /* purecov: inspected */
+    goto err;                                   /* purecov: inspected */
   buffpek.file_pos= my_b_tell(tempfile);
   if ((ha_rows) count > param->max_rows)
-    count=(uint) param->max_rows;                /* purecov: inspected */
+    count=(uint) param->max_rows;               /* purecov: inspected */
   buffpek.count=(ha_rows) count;
   for (end=sort_keys+count ; sort_keys != end ; sort_keys++)
     if (my_b_write(tempfile, (byte*) *sort_keys, (uint) rec_length))
@@ -844,6 +844,7 @@ int merge_many_buff(SORTPARAM *param, uchar *sort_buffer,
     if (flush_io_cache(to_file))
       break;					/* purecov: inspected */
     temp=from_file; from_file=to_file; to_file=temp;
+    
     *maxbuffer= (uint) (lastbuff-buffpek)-1;
   }
   close_cached_file(to_file);			// This holds old result