Properly merge modletters in: use M_, improve emojitrans2.pl

Fix arguable bug in treeprint.py

Author: clsn

Makefile

@@ -1,4 +1,7 @@
-all: emoji.compose
+all: emoji.compose modletters.compose
 
 emoji.compose: emoji-base emojitrans2.pl
-	./emojitrans2.pl < emoji-base > emoji.compose
+	./emojitrans2.pl < $< > $@
+
+modletters.compose: modletters-base emojitrans2.pl
+	./emojitrans2.pl < $< > $@