Allow $model->visible to declare custom accessors
Update existing pivot records on sync if they exist. Closes #1534.
Merge branch 'feature/custom-accessors' of https://github.com/cviebrock/framework into cviebrock-feature/custom-accessors
Make "guarded" take precendence over "fillable" in case key is in both by accident. Fixes #1545.
Reset select columns after aggregate query. Fixes #1516.