added katex
removed useless layout file because it was only used for one page
added katex font files, and added a render modal to input expressions
added katex rendering with optional equations
fixed bug where new boards do not have an entry in the usermanager class, which caused the first user on any board to not load because of an exception thrown on the server
fixed bug where some messages would be prepended by linebreaks by changing the message input from a textarea into an input of type text
working on improving chat system
removed useless cursor sending coordinates on mouse move to the server