Remove old classes of emoji

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>
Emoji drawer from bottom of the screen (thanks to TextSecure)

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>
Exclude TextSecure code from Checkstyle

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>
Emoji drawer with no back button support

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>