Fix various EasyChat bugs

[Tenrys]

Previous text history is horrible to mess with,
Ctrl+C will remove text in input
why is the chat not hidden when you have camera on

[Tenrys]

Turns out previous text history is due to Garry code being bad.
I will fix all DTextEntries at the same time, as well as adding more features like Ctrl+Backspace.

[Tenrys]

Nevermind, EasyChat is retarded.

I'll just end up making my own chat instead.