[Build] Reverted dependency change applied to the dev client
[Client] Improve keyboard movement

The movement of a character was not triggered in case the key to move
was just pressed a short time. This issue was caused by the delay timer
that is in place to allow proper movement with two keys. This issue is
now fixed. In case the delay timer did not expire, the movement is
triggered once the key is released.
[Client] Hide questmarkers in case the tile is hidden

Questmarkers of different map levels were visible in a unexpected way.
This is now resolved by hiding the markers in case the tile the marker
belongs to is hidden.
[Client] Display quest target locations on the map
[Client] Properly handle the start locations of quests

The quest locations are now properly removed from the scene graph and cleaned up in case the referring tile is removed.
[Client] Clearing quest start locations once the map is cleared
[Client] Catching problems at calculating the line of sight

The bresenham implementation caused a error to be thrown in case the
line got too long. While this indicates a error it shouldn't send the
client to hell. The most likely reason is that the line is calculated
for two character that are too far apart from each other. This error is
now caught and handled properly.
[Client] Improved overlay tile handling

The handling of the overlay tiles is not reduced to the bare minimum.
Along with the improvement in matters of performance this also solves
the hiding bug of the tiles with overlay.
[Client] Cleanup code for graphical tile
[Client] Show quest markers on the mini map
[Client] Adding a option to show and hide the quest markers

The options allow to hide and show the quest markers on the mini map
and/or on the game map.
[Client] Catching illegal directions in player movement
[Client] Delay execution of the quest available message

The message is now delayed until the GUI is ready and loaded
[Client] Properly updating the elevation

The elevation is now updated in case a new avatar is created
or the item on the map is changed.
[Client] Cleaning up animations
[Client] Applied changes for mantis connect
Merge branch 'release/2.1.8'