Renames some of the BBModel methods for retrieving values
BBModel::__get now returns values from $default_values (new objects only).  Adds BBModel::ref

ref() allows us to return values from reference methods (like &__get, &load etc), even if we don't necessarily want to return a reference

for example we may want to return false or null to indicate an error, or we may want to return
just the value and not a reference (when loading from $data etc).. so we wrap the value in
ref() and it returns a fake reference
Resolves conflicts from changes made at work