Enforcing a limit of 50 smilies per parsed message

Enforcing a limit of 50 smilies per parsed message

Exceeding smilies will be ignored:
- `<img>` will be reverted into the textual representation
- text smilies will be left untouched

The limit is enforced for both types of smilies that could occur, for
example having 47 smilies using `<img>` will cause at maximum 3 text
smilies to be converted into actual images.