Add experimental UTF-8 support
Get Unicode to work

Add UTF-8 decoding for standard input, which allows messages entered in
the console to match Unicode triggers from the RiveScript documents.
Update unicode.rs
Merge remote-tracking branch 'origin' into unicode
Fix the merge from master
Fix the decoding of inputs from UTF-8
Merge remote-tracking branch 'origin/master' into unicode
Make sure all inputs are Unicode in a safe way

Check if the input message is a str (not unicode), and decode it if so.
This makes UTF-8 mode work seamlessly in all use cases.
Merge the Unicode support into the master branch

Add notes about UTF-8 support to README.md, bump the library version
number to its odd development release version.