Dual Timer, a variant of the Stock Stopwatch (#236)

* init

* advanced latlon setting

* simple functionality done

* lat lon high precision fwd bwd

* edit toggle

* added readme for branch

* DD DMS conversion & cleanup

* DD to OLC conversion

* olc encoding & decoding

* OLC implementation

* swapped bools for modes, code cleanup

* place name editor

* updated button logic, fixed display

* load and save  places in state array

* todo list

* simplified OLC functions

* geohash conversion functions

* geohash display & digit functions

* todo

* finished geohash implementation

* code display function, defaults, bugfixes

* read/write file/reg logic

* long light in DATA to cancel

* write to registry

* todo

* read & write backup register

* file read/write

* todo

* new more concise button logic, optimizations

* todo

* renamed & cleaned up, fixed button logic

* documentation

* documentation

* LAP mode for all coordinate screens

* faster and more precise geohash algorithm

* updated description

* updated docu

* simple place face

* bugfixes, updated documentation

* init

* meh

* added public functions for OLC and Geohash

* randonauting face

* fix

* display fix

* cleanup

* bugfixes

* bugfix

* added place

* fixed TRNG call

* fixed declaration conflict

* modulo bias filter

* simplified things, chance RNG selection

* fixed button logic, better menus

* cleanup

* documentation

* docu fixes

* original README

* updated place_face

* fallback to register location

* removed pointless freq req

* init

* dual chronograph

* documented and cleaned up

* unused var warning fix

* swap TC2 with TC3 to avoid conflict

* conflict

* show active when returning to face

* docu

* removed unneeded file

* added remain

* show screen on startup

* simplified mode button

movement/movement_faces.h

@@ -87,6 +87,7 @@
 #include "invaders_face.h"
 #include "world_clock2_face.h"
 #include "time_left_face.h"
+#include "dual_timer_face.h"
 // New includes go above this line.
 
 #endif // MOVEMENT_FACES_H_