Merge pull request #2 from Playsure/feature/t16

Gallery model #16
Carrier wave with an uploader
Photo model with uploader
調整 photo form & show
Merge pull request #3 from Playsure/feature/t17

上傳照片 #17
Merge branch 'master' into develop
URL 與關聯初步調整
Controller 撈相對應的資料
Merge pull request #4 from Playsure/feature/t30

修復 GalleryCategory <=> Gallery, Gallery <=> Photo 之間的關聯問題 #30