Add Pods 'FXBlurView'
Add .gitignore
Design New Playing View UI

1. Remove songs table view, only info about the current playing music,
such as album picture, song, singer and album name, playing time, control button.

2. Auto layout for all screens.
Update Main XIB

Replay play, prev, next UIImage with UIButton
Add API `- [Song getSongByIndex:]`
Update Project Settings
Make New UI Works
Update README.md
Make Progress Bar Works
Bug Fix

If completionBlock is nil, the app will crash. Fixed.
Implement Play/Pause Button Action
Modify `- [Song getSongByIndex]`

Handle array index range problem using exception.
Implement Prev and Next Button Action
Add Page View Controller

Let page view controller manage the mvc (and song list view, channel list view)
Make Song Class a Singleton

1. Rename class `Song` to `SongStore`
2. Modify class `MainViewController` for `SongStore` change
Add New API `- [SongStore loadWithDataRefreshBlock:completionBlock`
Update `MainViewController`

Use new API `- [SongStore loadWithDataRefreshBlock]` instead of
`- [SongStore loadWithDataRefreshBlock]`. In case of unnecessary refreshing data.
Add `SongTableViewController` to Display Songs List

1. Add `SongTableViewController` to page view controller
2. Set `MainViewController` as the initial view controller of page view controller
Select Song Table Cell Can Change Song

1. Let `PageViewController.viewControllers` public for getting `MainViewController`
2. Let `- [MainViewController changeSong]` public for changing song
Allow Play in Background