Increased max TCP connections.
Some optimizations on how TCP relays are used.
DHT fixes.

This should speed up DHT searches.
Fixed test.
cs_set_video_encoder_resolution improvements.
Fixed some A/V threading issues.

Audio dropping on video calls issue should no longer happen.
Cut one on one default audio bitrate by half.
Removed calloc from logger_init, because the pid was no longer being appended.
Merge branch 'master' of https://github.com/irungentoo/toxcore into logger_init_fix
Build system fixes.

libtoxcore.pc now has -lpthread like it's supposed to on systems
where it is needed.
Added cscope.files to .gitignore
Merge branch 'logger_init_fix' of https://github.com/jdp5087/toxcore
Merge branch 'cscope.files' of https://github.com/jdp5087/toxcore
Merge branch 'master' of https://github.com/irungentoo/toxcore into new_groupchats