- get my_strtod to return inf
- get Field_float::store(double) and Field_double::store(float) to set null for 
nan value 
(as extra serg's recomendations to fix for patch on 
 Bug #2082 'mysqldump converts "inf" to null')


client/mysqltest.c:
  added commands --query_vertical and --query_horisontal
mysql-test/r/insert.result:
  converted testcase so as my_strtod can return inf now
mysql-test/r/mysqldump.result:
  converted testcase so as my_strtod can return inf now
mysql-test/t/insert.test:
  corrected tests to using --query_vertical instead of 
  pair (vertical_results,horisontal_results)
sql/field.cc:
  corrected Field_float::store(double) and Field_double::store(double)
  to set null for nan value
strings/strtod.c:
  get my_strtod to return inf