Possible regex fix for emotes with inequality symbols

Twitch performs HTML escaping on the symbols first, turning "<" and ">" into "&lt;" and "&gt;".
All symbols are then escaped for JavaScript's regex syntax: "\&gt\;" and "\&lt\;".
We then have to add another layer of escaping for Java's own regex (for replaceAll): "\\&gt\\;" and "\\&lt\\;".
Finally, last layer of escaping for Java's string literals: "\\\\&gt\\\\;" and "\\\\&lt\\\\;".

The replacement strings also need escaping (once for regex, and once more for Java string literals), since "<" and ">" characters have special meaning in Java regex (as part of lookbehind construct). So they become "\\<" and "\\>".

Partially fixes #37