Second Release

Change log (v1.3)

[Functionality]
1. Able to hide sticker packs, keyboard view should look cleaner now.
2. Able to send .png instead of .gif by long-clicking on the sticker.

[Bug Fix]
1. Gif is now default to white background, as transparency support on gif itself is kinda difficult. T^T
2. Fix some bugs that caused keyboard view didn't update after a change. (Adding sticker pack, etc.)
3. Some UI tweak ;)