The old getText method didn't handle multi-byte characters properly which would cause some bytes to get left behind. The lua string.match group %a also only matches ASCII letters so letters like 'ä' or 'µ' would not get matched.

Let's say you used the upper command on the string "hëllö". You would get:

• Before this PR: HëLL
• Now: HËLLÖ

I did not bother fixing the other more complicated methods (title, pascal, etc.) because I don't think they're often used and it would be rather complicated as Lua doesn't have great tools for handling Unicode characters. Micro exposes the strings package from Go, but you'd need to rewrite the whole thing to use it.

closes #15