Added insert/inserts to limit dao base class.
Also added $reload_model_from_source to dao and limit dao base classes, this is necessary to deal with data sources that update the content after it has been inserted/updated (eg, timestamps). This option is off by default since it has the extra overhead of reading from source immediately after writing.
Upon insert/inserts/updates the record is immediately cached to avoid any race conditions should there be a master/slave source set up.
Forgot in the last commit to do this: on update the record is immediately cached to avoid any race conditions should there be a master/slave source set up.