Add image compression, background colors

• Added the ability to set the background color in the editor.
• Added [Replace] and [Discard] buttons to the Compare dialog to provide a single-click way to replace the original note with a received note or discard the received note, respectively.
• Reworked the editor color pickers.
• Notes with images can now compressed when sharing. This reduces the number of sections.
  • If the receiver of the note is not running version 1.1 of the plugin, this will cause an error on their end when they try to view the note. Be sure everyone has updated to version 1.1 before using this feature.
  • Compressed notes are incomprehensible when seen in the chat window.
• Plugin should do a better job of matching mob notes with mob kills.
• Reworked the "find" and its highlighting to co-exist with user background colors.