Assorted terminal fixes

[wenottingham]

• catch terminal resizes on track change
• rename function to avoid having to #undef getch
• use atexit() to reset terminal settings in case of crash

[swesterfeld]

I merged the first two commits, which look good. I didn't merge the atexit changes, because they don't really help if the program terminates abnormally.

For this, we would need to handle SIGTERM, SIGHUP, SIGQUIT and fatal signals like SIGABRT, SIGSEGV.

[swesterfeld]

I didn't merge the atexit changes, because they don't really help if the program terminates abnormally.

For this, we would need to handle SIGTERM, SIGHUP, SIGQUIT and fatal signals like SIGABRT, SIGSEGV.