Update tiled_it.ts
Added Screen coordinates, taking the role of the old Pixel coordinates.
Map Objects are now in Pixel units internally.
Corrected IsometicRenderer's pixelToScreen/screenToPixel.
Merge branch 'screencoords' into mapobjectunitsv2
Updated object tools to use pixel units as needed.
Removed unnecessary conversions in IsometricRenderer.
Merge pull request #591 from mauvecow/screencoords

Renamed "pixel" to "screen" coordinates and introduced a new "pixel" coordinate type.
Merge pull request #592 from mauvecow/mapobjectunitsv2

Map Objects' internal representation converted to pixel units
Fixed snapping to grid when moving and pasting objects

When pasting objects it was dealing with pixel coordinates rather than
tile coordinates for aligning.

For the moving, the alignment position is now in pixel coordinates but
was still treated as being in tile coordinates.
Removed unused TilesetModel::mAllowDragging

In fact this property was not needed since the view already has an
option for this.

Coverity-issue: 1165683 (Uninitialized scalar field)
Cleaned up some strange MapObjectModel code

The MapDocument pointer of the model should not be changed. The model
is owned by the MapDocument after all. Also, there was no need for
the additional (and uninitialized) mMapObjectModel member.

Coverity-issue: 1165682 (Uninitialized pointer field)
Added support for moving image layers in the Properties window
Flare plugin: Removed unneeded null pointer check

Coverity-issue: 1165680 (Dereference before null check)
Lua plugin: Removed conversion from tile to pixel coordinates

This is no longer necessary since the units are already in pixel
coordinates.

Closes #611
Update tiled_it.ts

Removed "unfinished" tag from translated strings, and translated some others.
Merge pull request #588 from Omnomnobot/patch-3

Italian translation updates
Added read-only tile ID property to Properties window

Displays the local tile ID of a tile, which can be useful in some cases.

Closes #15
Avoid wrong removal of objects when resizing the map

Since object coordinates are now in pixel coordinates, the visibility
check of the resize operation was wrongly determining most objects were
outside of the map boundaries and removed those objects. Now it should
correctly take the pixel coordinates into account. At the same time,
handling of tile objects and object rotation was added.

While working on this I found another bug however, which is that the
object positions are not adjusted correctly. This is because the
correction is still applied in tile coordinates.

Closes #617
Fixed position adjustment of objects when resizing map

The same issue still affects the "Offset Map" action, though.