Fix scope, ressource leaks in boostrap daemon

Reduce scope of config_setting_t *elem

Fix various leaks of files keys_file and pid_file
Made av public header C++-enabled
Removed IRC references
Preparation work to make onion packets go through TCP.
Merge branch 'av-fix' of https://github.com/nurupo/InsertProjectNameHere into nurupo-av-fix
dns3_test now automatically does the DNS request.

tox_decrypt_dns3_TXT no longer needs id_record to be null terminated.
Merge branch 'bootstrap_daemon-leaks-1' of https://github.com/tux3/toxcore into tux3-bootstrap_daemon-leaks-1