modified for errors preventing, and data correcting.

after using such NotORM_Literal("now()"), we hope to get the actual values persistent.  So I reload the row data after using NotORM_Literal. 

when we do  table->insert($data) or table->save($data), if we got some wrong keys which are in table in $data, we will get statement error. For preventing this, I create a function to filter them.

Last, I often write a wrong table name, but NotORM execute normally and return null. It's hard to debug because I don't know which error took place, wrong table name or no record(s) returned.

OK. That's all.