Refactored the GUECS system to have its own namespace then got Meter to work.

meson.build

@@ -61,7 +61,7 @@ sources = [
   'config.cpp',
   'dbc.cpp',
   'devices.cpp',
-  'ecs_gui.cpp',
+  'guecs.cpp',
   'gui.cpp',
   'inventory.cpp',
   'lel.cpp',
@@ -92,7 +92,7 @@ executable('runtests', sources + [
   'tests/base.cpp',
   'tests/dbc.cpp',
   'tests/dinkyecs.cpp',
-  'tests/ecs_gui.cpp',
+  'tests/guecs.cpp',
   'tests/fsm.cpp',
   'tests/inventory.cpp',
   'tests/lel.cpp',