Port of timer_face from legacy (#64)

- Closes https://github.com/joeycastillo/second-movement/issues/15
- Fixed issue with colon disappearing if exiting settings mode on the CLEAR or LOOP strings
- Use newer print function with fallback for classic display

watch-faces.mk

@@ -38,6 +38,7 @@ SRCS += \
   ./watch-faces/complication/kitchen_conversions_face.c \
   ./watch-faces/complication/periodic_table_face.c \
   ./watch-faces/clock/ke_decimal_time_face.c \
+  ./watch-faces/complication/timer_face.c \
   ./watch-faces/complication/simple_coin_flip_face.c \
   ./watch-faces/sensor/lis2dw_monitor_face.c \
   ./watch-faces/complication/wareki_face.c \