Read tilesets with individual tile images (external or inline base64-PNG)
Write inline images for individual tiles for tilesets w/o external image.
Keep the max tile width/height as the tileset's tile dimensions
Display small tiles bottom-left aligned
Fixed resolving of symbolic links while loading map

When resolving references to external tilesets or images, it is important
to avoid resolving symbolic links. It can cause the generated relative
path when saving the map to be unnecessary complicated and possibly point
to undesired locations.

Cleaning the path should suffice for determining whether two tilesets
are the same in general.

Fixes #212
Fixed Qt 5 compilation issues again

Qt 5 is being a bit more strict with the QT_NO_CAST_FROM_ASCII define
than Qt 4.
Updated the GPLv2 license to its latest version
Added an option to disable the use of Rpath

When Tiled is installed to a standard system location, it doesn't
generally need an Rpath to find the libtiled library.

This commit adds the option of passing `RPATH=no` to qmake to suppress
the usage of Rpath in the tiled executable and its plugins.
Added initial Travis CI configuration file
Ignore automappingconverter.exe
See if Travis CI can build Tiled with clang
Fix tileset zooming

Adding support for various tile sizes in a tileset broke
Ctrl+scrollwheel zooming because the zoom level was ignored.
This fixes the regression.

Fixes #278
Added reading support to Flare plugin
Merge pull request #244 from o11c/master

Respect existing layer format of all loaded maps.
Fixed small documentation error
Removed unneeded include

layer.h is already included in the header file.
Moved layer data format preferences handling to TmxMapWriter

It doesn't really belong in MapDocument. The main reason however is that
doing it in MapDocument would conflict with the next patch.
Save As dialog can save in all formats it is safe to save in

* All Plugins, which can be read as well, can be used for
  saving as well.

* MapDocument class contains a new member (mWriterPluginFileName),
  which determines in which format the map should be saved.
  (It needs to be set accordingly, when opening a new File)

* The plugin manager has some more conversions.

* MapDocuments setFileName (only used by its saving function)
  is private now.

Closes #18.

Reviewed-by: Thorbjørn Lindeijer
Introduced a minimap

This is a quite stable running navigator or minimap.

With the help of MapRenderer a small version of the map is rendered into
a buffer image. The minimap rendering is copied from the screenshot
function and offers several flags to finetune the rendering.

For detecting mapchanges I used the indexChanged-event offered by
QUndoGroup. That does a pretty good job. Minimap rendering can be
expensive as it has to draw the entire map. To prevent slowdowns during
painting an (optional) timer is used that drops all redraw calls until
100ms are elapsed.

The overall performance impact seems to be okay. At least on my machine
(win7 64bit, quadcore i7 with good graphics card). This certainly needs
to be tested in different environments.
Fixed some compiler warnings

Unused variable and initialization order warnings.