Stream block uploads and compress cached mouth crops

.gitignore

@@ -28,6 +28,8 @@ static/arthur/js/
 # the Django half's own state: the document database, the content-addressed blob
 # store (tiers 2 and 3), and collectstatic's output
 db.sqlite3
+db.sqlite3-shm
+db.sqlite3-wal
 /var/
 
 # vim swap files