[compositor] don't add overlay windows to WindowModel
[lipstick] Queue a window update on map/unmap/surface damage

Calling QQuickItem::update is not always enough to guarantee
QQuickWindow frame swap, which is in turn is used to trigger
frame callbacks to clients. If a client expects a callback
but due to, for example, scene graph sync/paint optimizations,
a frame swap is skipped, it might cause a deadlock in the client
until the compositor draws a frame. Thus, schedule a repaint
always.
[lipstick] Remove preview body and summary from notifications when the category definition file is updated
Bump version
Merge pull request #78 from faenil/overlay

[compositor] don't add overlay windows to WindowModel
Merge pull request #81 from mikkoharju/update

[lipstick] Queue a window update on map/unmap/surface damage
[lipstick] No throttling when compositor is hidden

 - For power consumption, clients should not post frames
   when compositor is hidden.

 - But, for reliability, compositor should not block clients
   even though it is hidden.

 => This commit touches the second issue. Another fix should
    be done for announcing display off for clients.
Merge pull request #86 from mikkoharju/displayoff

[lipstick] No throttling when compositor is hidden
[lipstick] D-Bus service for taking screenshots