also test the mosql.result
removed a duplicate statement
a quick fix of the stupid update SQLs
use util.default as the hyper NOne
use better approach to avoid the stupid update query
merged to ident
use better way to clear
fixed a typo
reworded doc
added doc for default and star
updated doc
updated change log
rewored
make it better
return None if no row returns from a select
updated change log
changed version to v0.5.1