Update error message.
Debug.
Add emoji format of "seal", "hanko", and "px512".
Change stamp's emoji format to seal.
Replace word of stamp to seal.
Change emoji format of keyboard key icon.
Merge pull request #21 from emojidex/seal

Seal
Update EmojiDownloader.
Update DownloadListener.
Use new downloader.
Debug.
Remove trush.
Merge remote-tracking branch 'origin/downloader' into search
Debug.