Re-introduce missing copyright notice

The license under which Limechat's source code appears to have been forked to form the basis of Textual stated: "[r]edistributions of source code must retain the above copyright notice". This makes your license compliant with that.
Possible solution to #399 about original copyright. Include acknowledgements file in source root to make it easier to find and include copyright in README for original author.
New JavaScript APIs
Merge pull request #399 from mortice/patch-1

Re-introduce missing Limechat copyright notice
Fix formatting
Newer status icon removes all mentions of Colloquy from Textual.
Include copyright in source files originating from Limechat. The original source files never contained an actual copyright, only a reference that the file is licensed under the BSD license and a small comment saying "Created by Satoshi Nakagawa" — this commit adds an actual copyright for the original author. In reference to #399
Include reference to Colloquy's chat core license in source. In reference to #399
Fix control+click in text field.
Dark mode channel status icon.