Add verbose log file output option

[GooberRF]

I suggest adding a function to Dash, mostly for debugging/troubleshooting purposes, to log all console output (chat messages, command command output, informational logging, etc.) to DashFaction.log, as opposed to the current behaviour where only certain output, like errors and warnings, is logged.

This feature would be very useful to mappers/mod developers in that the output of debug commands (like event_debug_msg) would be accessible in text form for troubleshooting purposes. There are a number of other cases where it would also be useful for troubleshooting purposes - for server operators, players, etc.

My suggestion would be to implement this as a tickbox in Dash options, and also allow for it to be toggled via a console command (similar to fps_counter and bighud, for example). Alternatively, if you consider this more of a dev/debug feature which shouldn't be as visible/accessible, implementing it as a command line switch would also work.