Add comment's for enable/disable_query_log and enable/disable_result_log
Update comment for "check_result"
Add check in "handle_error" that detects if the server crashed when running a "require" query to check if a certain feature is available


client/mysqltest.c:
  Add comment's for enable/disable_query_log and enable/disable_result_log
  Update comment for "check_result"
  Add check in "handle_error" that detects if the server crashed when running a "require" query to check if a certain feature is available