* Use MutationObserver to detect when new messages are scrolled into view or new messages are received.
* Add decrypt buttons to all elements at once, instead of using a mouseover event.
* Fix decrypt buttons not being added to some messages (images, styled text, emojis), even though they couldn't be decrypted anyways.
* Press the decrypt button to "re-encrypt" the message if it's decrypted. This sets the text back to its original state instead of modifying it!
* Replace `String.match` with `String.search` in some cases due to bad performance in Firefox (JSPERF: 50% slower -> 3% slower compared to indexOf).
* Better method of getting the current channel ID.
* Remove "clearing" the box after sending a message since it didn't work.
* Fingerprints stored in localStorage don't need to be parsed, and would throw an error if they were.
