[lipstick] Connect notify signal for window title changed

When the surface's title property changes, send a notification. Also
establish a slot for handling for future surface connections.
[launchermodel] Remove unnecessary check for existing watch

From the Qt 5 docs: The path is not added if it does not exist, or if it
is already being monitored by the file system watcher.
[launchermodel] De-duplicate launcher settings handling

Combine duplicate code paths and avoid re-instantiating QSettings
objects all the time in different functions at the cost of having
two QSettings objects alive during the lifetime of the model.
[launchermodel] Allocate file system watcher on the heap
[launcheritem] Force reload by re-using setFilePath()

De-duplicate the code here as well to make it easier to maintain.
[launchermonitor] Rewrite monitoring of .desktop and icon files

Fixes problems where the launcher wouldn't find the icons in the right
location for some cases. Right now, this hard-codes the icon size to
86x86, but it can easily be extended later to pick a given icon size
and/or monitor multiple directories.

Monitoring of multiple directories with .desktop files is currently not
supported, but can easily be added (it wasn't utilized before as well).
[launchermonitor] Remove only one item per iteration
[launcher] Clarify some comments
Merge pull request #114 from thp/launcher-monitoring

Launcher monitoring
[launchermonitor] Don't send modified updates for added/removed files

Avoids bogus "modified" updates when a file appears and vanishes again
(e.g. for temporary files that are created during package installation).
[launchermodel] addItemIfValid should return LauncherItem *

Allows us to check whether the launcher icon has really been added.
[launchermodel] Check for existing icon when adding .desktop file
Merge pull request #115 from thp/launcher-install-load-icon

Look for existing icons when adding a .desktop file, fix extraneous "modified" file updates
[orientation] Don't change orientation on face up / face down
Merge pull request #116 from thp/keep-orientation-on-faceupdown

[orientation] Don't change orientation on face up / face down
[lipstick] Make a copy of retained selection

The retained selection was inappropriately passing the compositor's
mimeData pointer to QClipboard, leaving the possibility for the object
to be get deleted twice.
Merge pull request #107 from xknight/master

[lipstick] Connect notify signal for window title changed
Merge pull request #117 from xknight/clipboard

[lipstick] Make a copy of retained selection
[lipstick] Fix devicelock to use QSettings and not GConf