Add X11 option
Merge pull request #236 from s3erios/master

Some code simplification
Merge pull request #235 from s3erios/master_cfg

Add X11 option
Add info about DISABLE_X11 usage
Merge pull request #238 from Ansa89/trivial-fix

Addition to Tox/toxic#235
fix potential memory leak and move cleanup to the end of the function
mark exit_toxic_* functions as _Noreturn
fix another potential memory leak