Improve level metadata display and font handling

- If the level font is higher than 10 pixels, the third description
  line (Desc3) is disabled and unavailable. CJK languages require less
  characters to convey the same message (140 characters caused people
  to cram tweets in all languages except CJK) and this gives us enough
  room in the levels list without having to cram the metadata even more
  than it already was or showing less levels per page.
- The "Untitled Level" and "by Unknown" now selectively show up in the
  interface font instead of the level font.

desktop_version/src/CustomLevels.h

@@ -58,6 +58,11 @@ struct LevelMetaData
     std::string timeModified;
 
     int version;
+
+    /* true if a system "Untitled Level"/"Unknown"
+     * was stored in this struct (for the levels list) */
+    bool title_is_gettext;
+    bool creator_is_gettext;
 };
 
 struct CliPlaytestArgs
@@ -160,9 +165,9 @@ public:
     bool onewaycol_override;
 };
 
-std::string translate_title(const std::string& title);
+std::string translate_title(const std::string& title, bool* is_gettext);
 
-std::string translate_creator(const std::string& creator);
+std::string translate_creator(const std::string& creator, bool* is_gettext);
 
 #ifndef CL_DEFINITION
 extern customlevelclass cl;