Bootstrap3

Big change

Doorkeeper use deprecated bootstrap version, end-user and management UI using the same layout, not flexible, so this PR make these change:

- separate end-user and management UI & layouts, easy customize.
- upgrade bootstrap to 3.0.3
- rewrite views, solved many bugs

fix bugs:

- when using test URI and deny the authorize will raise ```URI::InvalidURIError```
- ```redirect_uri``` has checked field present, given ```presence: true``` will duplicate ```Can't be blank``` message

enhencements:

- default use 4.0.2 as development Rails dependency
- add Rubymine project folder to ```.gitignore```