FIX: Minor fixes to text and better warnings for gloo

Ready for review/merge.
@almarklein I couldn't run your demo without this on Py2.7 OSX. You had utf-8 strings in your code, but they were being represented as `str` (ASCII). Then when iterating over them, you get individual bytes instead of the correct UTF8 characters. Always decoding to utf-8 fixes this issue. I haven't tested it on Linux, but it should work there, too.