refactor/cleanup to mapper options methodology to allow for incoming defer/undefer...

refactor/cleanup to mapper options methodology to allow for incoming defer/undefer options
mapper/relations are stricter about class attributes and primary mapper - is_primary flag
on relations fixed (wasnt working before). new primary mappers clear off old class attributes,
secondary mappers insure that their property was set up by the primary; otherwise secondary
mappers can add behavior to properties that are unmanaged by the primary mapper
added "group" option to deferred loaders so a group of properties can be loaded at once
mapper adds the "oid" column to the select list if "distinct" is set to true and its
using the default "order by oid" ordering (mysql benefits from ansisql fix to only print out unique
columns in the select list since its oid is the same as the pk column)
fixed unittests to comply with stricter primary mapper rules