Add variable to disable messages indicating window placement

When a window is placed by a rule that had :raise nil, a message is
displayed. This patch introduces the
variable *suppress-window-placement-indicator* that if set to t will
never display these messages.
Add select-from-menu to export list
Merge pull request #56 from scottjad/window-placement-message

Add variable to disable messages indicating window placement
Merge pull request #57 from scottjad/export-select-from-menu

Add select-from-menu to export list