Update BUILDING.md

Correction of a typo and a few style incongruences.

// FREEBIE
Closes #1750
Fix emoji backwards compatibility recents crash

The old emoji drawer stored emoji with a .png suffix. Replace it during
list deserialization.
Add a backspace key to the emoji drawer
Remove gray placeholder squares while loading emoji
Occupy all vertical space for emoji grid

Fixes the recent emoji list leaving an empty gap at the bottom of the
drawer depending on the number of items shown.
Whoops, add GcmRegistrationService to Manifest.

// FREEBIE
Updated language translations.

// FREEBIE
Bumping version to 2.1.2

// FREEBIE
Basic support for feature 520
Save drafts for recipients without an existing thread
Clear drafts when deleting conversation(s)

- Also don't save drafts when the thread was deleted from the
 ConversationActivity menu

otherwise the drafts stay in the database and will reappear when a thread
with the same threadId is created
Show Drafts in ConversationList
fix io on ui thread, parameter substitution
use StringBuilder, rename method, extracted separate SaveDraftTask class
character counting when sms fallback is disabled but direct sms enabled
Revert "temporarily disable encrypted backup"

This reverts commit 5121ab0eed935e24a7c2617d5df12fd92b6115e8.
always enable emojii for me