Added Transifex configuration
Fixed possible crash in TileDelegate

This crash is not possible to trigger when using the UI to add tilesets,
but by editing the map or tileset file you can set up tilesets that
have a tile count that is not divisible by the column count. The
TileDelegate was not dealing correctly with table cells for which no tile
exists.
Removed ability to change terrain through the TilesetModel

It is no longer used and would not handle undo correctly.
Remember the size and position for some dialogs

Some dialogs were excluded from this behavior because they were either
not resizable or because it's probably better for them to always pop up
in the center (like Preferences, New Map and New Tileset).

Unfortunately for some window managers this behavior is broken and I
don't know of a good way to fix that. On Xfce for example, the dialogs
will move down by the height of their title bar each time they are
opened.

Closes #339
Fixed deletion of tilesets that are shared with open maps

When opening a map with external tilesets, it will share those external
tilesets when they are the same as those used in already open maps. When
some error is encountered while opening such a map, these shared tilesets
should not be deleted.

This patch makes sure that the map reader will only delete the tilesets
that it created itself while loading a map.

Fixes #312
Updated NEWS file
Tweaked the default window layout

* Mini-map is now tabbed beneath the Layers dock
* History and Maps docks moved to the right and are hidden by default
* Default window size was increased from 800x600 to 1000x700
Flareplugin: initialize number base to 10 when reading maps.

The default of flare maps is 10.

This commit removes the compiler warning:
..\..\..\..\tiled\src\plugins\flare\flareplugin.cpp:170:60:
warning: 'base' may be used uninitialized in this function
[-Wmaybe-uninitialized]
Removed an unnecessary separator in the tileset dock
Fixed Object Properties dialog not remembering its size

It was always resizing itself to its preferred size, so the mechanism
implemented in 28ea563 was not working for this dialog.

Fixes #339
Open Object Properties dialog when double clicking on object

Closes #300
Export/Import map background color to/from JSON
Depend on zlib directly when compiling against Qt 5

libtiled.pro is now set up to auto-detect a zlib installation at its
default location. When it is installed somewhere else, then the
environment variable 'ZLIB_PATH' should be set to the directory where the
'include' and 'lib' directories can be found that include zlib.

When compiling with MinGW, it will choose the static library to avoid
the need to copy a .dll around. When compiling with MSVC it will need the
zlib1.dll since I don't think the static library is compatible with that
compiler. The MSVC build has not been tested yet.

It expects zlib to be installed by using the package available at
http://gnuwin32.sourceforge.net/packages/zlib.htm

Closes #285
Simplified IsometricRenderer::pixelToTileCoords
Import/export terrain information from/to JSON

Fixes #350
Bump the maximum tile margin and spacing in New Tileset dialog

The maximum was at 99 pixels and somebody was hitting that limit. The
main reason for the maximum is because QSpinBox determines its size
based on the maximum value. With the current layout, the maximum can be
9999 and it will still be the same size, because it's aligned to the
tile size spin box anyway which has that maximum already.

Closes #359
libtiled-java: Added zlib compression support to TMXMapWriter
libtiled-java: Do not output width and height for ObjectGroup

It's obsoleted.
libtiled-java: Do not store firstGid in each TileSet

Instead, they should be calculated on-the-fly when writing a TMX file.
Loading TMX files should parse the gids while the file is being loaded,
but not persist them inside the TileSet.
libtiled-java: Added support for caching tilesets

For example, when reusing the TMXMapReader to load several TMX files
that all have the same tileset definitions, the loader does not have to
load the tileset images several times, thus making the loading process
much faster.