perf tui: Catch signals to exit gracefully

Resetting the terminal to a sane state.

Reported-by: Ingo Molnar <mingo@elte.hu>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-myu44ujofadcy3y6an2mk383@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>