evtone: Use sigaction instead of signal

evtone: Write errors to stderr

evtone: Use sizeof(event) instead of sizeof(struct input_event)

evtone: Release 1.2

evtone: Check return of write() properly

evtone: Release 1.1

evtone: Use sig_atomic_t for got_signal ...

Strictly speaking, 'volatile int' is not guaranteed for atomic writes by
the C standard. However glibc says in practice 'volatile int' should be
fine. Fix it either way.

Initial commit