Bring back the gdx-tiled-preprocessor tool

Add tool back to the ant build script
Reset org.eclipse settings to the same as gdx-tools (formatter profile)
Reimport test data
Refactored to use the new TexturePacker2.
Add support for ImageProcessor to accept BufferedImage objects as input
Update TexturePacker2 to accommodate ImageProcessor changes and exposes new
constructor and method.
Added me to CONTRIBUTORS file
Fixed tile removal feature, track usedIds per-tileset spawning across
different maps

Also refactored and removed old unused code.
Minor refactoring
Packing tilesets should walk all used tilesets, not only the last one

Previously the last loaded Map object was used to walk the tilesets and
pack them, now tilesets are being tracked consistently and enumerated
correctly.

Minor refactoring.

Add support for packing and loading multiple atlases in a single map,
adding a custom map property "atlas_<tilesetname>" to link a tileset to its
atlas.
Add new Tiled map loader with TextureAtlas support

Initial code from Justin Shapcott, thanks for sharing!

Port all changes from latest TmxMapLoader, load more map properties, check
for correct encoding
Minor refactoring
Add support for force-enabling custom texture filters
Add support for multiple TextureAtlases
Add null parameter check before use
Add new tests for TiledMapAtlas direct loading and AssetManager loading

Add resources (+preprocessed) to be able to run tests on checkout.

Note about resources: the "tiled-atlas-src" directory contains the source
used to build the "tiled-atlas-processed" resources: you can build the
preprocessor by running "ant -f build.xml gdx-tiled-preprocessor" in the
root libgdx/ directory.

Once built, run it against the source data, specifying an input and an
output directory:

<packer> <libgdx/.../tiled-atlas-src> <libgdx/.../tiled-atlas-processed>

Note that at this time the preprocessor will NOT overwrite the destination
folder if it already contains the same data, so make sure it's clean.
Fixed setting texture filters on a non-rendering thread
Respect filter settings also in synchronous loading
Minor refactoring
Better resource management when the AssetManager is not used

This permit the removal of AtlasTiledMap whose reason to exist was to track
resource usage only.

Changes propagated to other loader and tests as needed.
Alternative version that builds one single TextureAtlas for all the tiles
across all tilesets, for any processed map instead of splitting the result
into multiple atlases.
Merge remote-tracking branch 'upstream/master' into gdx-tiled-packer-redux-gles2
Merge remote-tracking branch 'upstream/master' into gdx-tiled-packer-redux-gles2
Various fixes

Uses better name for packed tilesets
Update preprocessed test resources.
Do not create a new StaticTiledMapTile if it's of no use
Remove unneeded references
Do not add "blended tile" property anymore, more javadocs
Use listener class name if title is null.
Merge remote-tracking branch 'origin/master'
Add back the "blended tiles" property

The rendering will introduce blending optimizations at some point.
Fixed, effectively set blended tiles
Remove Gdx.files dependency by using a custom FileHandleResolver

Update javadocs accordingly.

Now only graphics resources impose the creation of a LwjglApplication: this
is probably subject to change in the future, where loading both maps
metadata and graphics resources should be made conditional.