Activity face + Chirpy TX (#187)

Activity face + Chirpy TX (#187)

* chirpy demo face; activity face stub

* activity face WIP: can log, pause and clear

* activity face and chirpy demo: ready to flash to watch

* activity face tweaks

* hour display for hours < 10

* fix: added rogue paused seconds when stopping activity

* LE mode; lower power with 1Hz tick

* fix: midnight is 12

* Documentation in code comments

* fixes from code review by @neutralinsomniac

* chirpy_demo_face option to chirp out nanosec.ini + auto-format

* UI tweaks

* remove erroneously added file (content revoked)

* UI tweaks: return from LE mode; time display vs LAP

* add default loop handler (will enable long-mode-to-first-face)

* reset watch faces to match main branch