windows: add missing event functions

Add CreateEventEx, OpenEvent, ResetEvent and PulseEvent.

Also change eventAttrs to use the local definition of the
SecurityAttributes type, not the one from syscall.

GetConsoleScreenBufferInfo is also changed by re-running 'go generate'
to pass a pointer to ConsoleScreenBufferInfo (instead of a pointer to
pointer).

Change-Id: I08dff4360186b04c55fd0362e31920f38206157b
Reviewed-on: https://go-review.googlesource.com/56110
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2 files changed