Misc patches, especially adding preload_all into initializer

[Rails 5] Add manual preload into initializer as well (#64)

* add manual preload into initializer as well

* patch version

New design and better structure of controller/servicer

see Changelog

Bugfixes and add password field support

1. Bugfix: database migrations fail when decorator invokes form_fields and table does not exist (issue 4)
2. Feature: Add partial to support password field (issue 9)
3. Bugfix: Using the right metadata for index/show/form partials respectively (issue 12)

Bugfixes and add password field support

1. Bugfix: database migrations fail when decorator invokes form_fields and table does not exist (issue 4)
2. Feature: Add partial to support password field (issue 9)
3. Bugfix: Using the right metadata for index/show/form partials respectively (issue 12)

Support Rails5

Support Rails5

Support for Devise 4

Support for Devise 4

Minor fixes for NameError and public_send

1. Bugfix: rescue NameError for Rails reload
2. Bugfix: replace send to public_send

foreign_key instead of association_foreign_key for belongs-to

1. Bugfix: when it's belongs-to relationship, it should take foreign_key instead of association_foreign_key as foreign key.

Moved all helpers into lib so that they won't be shared with main_app

1. Moved all helpers into lib folder and included these helpers explicitly in controllers so that they won't be shared with the main_app
2. Resolved an assets issue for summernote by dynamically converting summernote.css into wallaby/summernote.scss

Update view paths precedence

1. Update view paths precedence from high to low:

   • app/views/WALLABY_ENGINE_MOUNT_PATH/RESOURCES_NAME/*
   • app/views/CUSTOM_CONTROLLER_PATH/*
   • app/view/wallaby/resources/*

   WALLABY_ENGINE_MOUNT_PATH is the path where wallaby engine is mounted to. e.g. admin
   RESOURCES_NAME is the path formed by model class's plural noun. e.g. order/items
   CUSTOM_CONTROLLER_PATH is the controller path of the controller that inherits from Wallaby::ResourcesController

2. Bugfix: replace @import with require for summernote to avoid error invalid byte sequence in UTF-8

3. Enforce wallaby application controller to use designated layout wallaby/application especially when it inherits from main app's application controller.

4. Rescue pagination entry from throwing error when Kaminari is not used.