UTF-8 and Optionals

[kirsle]

This might be related to rivescript-js#147. The following test case produces the problem:

+ *
- Häää?

+ [*] (überrasch mich|empfiehl mir was|empfehl mir was|was gibts neues für mich|empfehlung) [*]
- recommendation

The words with umlauts in them make the second trigger unmatchable.

In rivescript-js#147 I found Python wasn't affected by the Chinese symbols but may be having problems with these umlauts for some reason.

[Xiangshen-Meng]

Maybe the Chinese symbols problem is caused by space.
https://github.com/aichaos/rivescript-python/blob/master/rivescript/brain.py#L449
For language doesn't separate by space(Like Chinese), this line may cause problem.

p = r'(?:\\s|\\b)+{}(?:\\s|\\b)+'.format(p)

How about change it to this?

p = r'(?:\\s|\\b)?{}(?:\\s|\\b)?'.format(p)

But this may cause the English in word optionals.

Sorry I am not familiar with RiveScript and this is only my thoughts.

[kirsle]

Fixed by PR #108