fixes#194 Starting multiple screen sessions (lost key event)
You can test this by using the mouse demo, which now supports pressing
CTRL-Z. This does not actually suspend the demo, but starts a subshell
which takes over. After the subshell is exited, the demo takes control
of the screen back. This can be done multiple times, and it is possible
to start multiple "nested" iterations of the demo this way.
This adds optional MouseFlags that can be used to adjust what is
tracked for mouse reporting (leaving the other modes to be handled
by the terminal.) This should work on all XTerm style terminals,
but on Windows we have no way to be selective here.
This adds Bracketed Paste support for terminals that have mouse
support and support it. The bracketing events are EventPaste,
with methods to note Start() or End() of the paste. Content
comes in as normal rune events. Programs must opt-in to this by
calling screen.EnablePaste().
Add a Beep() method to the Screen interface. On *nix systems, this
writes the bell character (0x07) to the tty. On Windows, we call the
MessageBeep syscall.
Fixes: #2