show/hide userslist #459

Added an icon in the index.html.tmpl underneath app_tools.
Added the event handler for the icon in apptoolbar.js.
Fixed a bug where CANNOTSENDTOCHAN misfired its bug and add a feature to where cannot_send_to_chan is mentioned in the client
Merge commit '1dad9adf52db07b5b38139f21b78b490cd277c78' of https://github.com/DaHispanicNinja/KiwiIRC into development
Merge commit '55a324629a07da2985ba84c0d39905a6cee7a247' of https://github.com/crtaylor123/KiwiIRC into development