TextObject fix.
* Get Unicode string. Shows up in clang but not GCC.
Fix bad virtual override.
* SetValue(int) clashes with SetValue(string). Renamed to SetIntValue(int). Reported in clang.
Fix remaining signed/unsigned warnings
* This seems to fix the 64 bit and signed/unsigned warnings in GWEN for
  GCC and clang (Xcode).
* size_t cast to 32 bit unsigned int. GWEN assumes 32 bit compilation.
  This is good enough. GWEN would need a fair bit of work to make 64 compliant.