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.

include/m_string.h

@@ -215,7 +215,7 @@ extern char *strstr(const char *, const char *);
 extern int is_prefix(const char *, const char *);
 
 /* Conversion routines */
-double my_strtod(const char *str, char **end);
+double my_strtod(const char *str, char **end, int *error);
 double my_atof(const char *nptr);
 
 extern char *llstr(longlong value,char *buff);