Optimize reading screen data from Dfhack Dfterm3 plugin.

Profiles told me this part uses the most resources. Unfortunately I was
incapable of optimizing it significantly.

This changed the Dfhack<->Dfterm3 protocol so you should update Dfhack Dfterm3
plugin.
Disable Nagle's algorithm for Websocket connections.

Latency over throughput. This should be as real-time as possible.
Add some things to .gitignore
Merge branch 'ui' of git://github.com/lethosor/dfterm3

Lethosor made some wonderful user interface changes. We must merge them.

Reviewed-by: Mikko Juola <mikjuo@gmail.com>
Don't print the process id to stdout when connecting to Dfhack.

For some reason, there was a "print df_pid" written in the connection code.
Every message is supposed to go through the logging system so that they get to
the correct place.
Fix compilation warnings and fix all hlint reported warnings.

I also enabled the Linux Dwarf Fortress executing again.
Remove useless tick printing.