Support text symbol.

a

eek/eek-types.h

@@ -140,6 +140,7 @@ typedef struct _EekSection EekSection;
 typedef struct _EekKeyboard EekKeyboard;
 typedef struct _EekSymbol EekSymbol;
 typedef struct _EekKeysym EekKeysym;
+typedef struct _EekText EekText;
 typedef struct _EekTheme EekTheme;
 typedef struct _EekThemeContext EekThemeContext;
 typedef struct _EekThemeNode EekThemeNode;