Fix initializer list issue with ZoneOptionValue (#4203)

* [480x272] Fix initializer list issue with ZoneOptionValue (technically not C++11), now works x-platform as well, lowers Flash use; Spit out Zone, ZoneOption, ZoneOptionValue to own unit. (Fixes https://github.com/opentx/opentx/pull/4199/files#r94867147)

* [480x272] Revert to Flash usage for ZoneOptionValue types (still fixes MSVC build). (Ref: https://github.com/opentx/opentx/commit/82dce3ee601049cf548ff4518902ab8e8fa62a0b#commitcomment-20388918 & https://github.com/opentx/opentx/pull/4199#discussion_r94835251)

* Cosmetics.

* [480x272] Cosmetics.

radio/src/gui/480x272/widgets/text.cpp

@@ -20,6 +20,8 @@
 
 #include "opentx.h"
 
+#define TEXT_WIDGET_DEFAULT_LABEL  '\15', '\347', '\0', '\14', '\377', '\376', '\373', '\364'  // "My Label"
+
 class TextWidget: public Widget
 {
   public:
@@ -34,7 +36,7 @@ class TextWidget: public Widget
 };
 
 const ZoneOption TextWidget::options[] = {
-  { "Text", ZoneOption::String, OPTION_VALUE_STRING('\15', '\347', '\0', '\14', '\377', '\376', '\373', '\364') },
+  { "Text", ZoneOption::String, OPTION_VALUE_STRING(TEXT_WIDGET_DEFAULT_LABEL) },
   { "Color", ZoneOption::Color, OPTION_VALUE_UNSIGNED(RED) },
   { "Size", ZoneOption::TextSize, OPTION_VALUE_UNSIGNED(0) },
   { NULL, ZoneOption::Bool }