#87 activate-window options

[Guido Boehm]

against version: todays cvs

adds:
- 'session.activateWindowActions' .blackboxrc-option
which takes "None" , "Raise", "Unshade" or any
combination of these 3 as a value.
- new submenu inside 'Configmenu' labled
"Activate-Window Actions", which has 2 toggle-able
items, "Raise" & "Unshade"

background:
if a window gets activated by some EWMH tool sending
a '_NET_ACTIVE_WINDOW' message the spec says a window-
manager should take any action required to give the
window the input-focus. depending on the wm this might
be uniconify, switch to workspace, etc.
next to this bb 0.70 chose to unshade the window and
raise it, too.
since this is not really required to let a window get
the focus this patch makes it optional.

other:
i made the BScreen::prevFocus/nextFocus methods aware
of this setting to let it look consistent.
i don't know if other 'window-activation-things' like
clicking on a window in 'Workspaces'-menu should obey
this option as well or if it is better to still provide
some alternate focus-method.

// lenix

[Guido Boehm]