Fixed compilation on VS 2008

It does not support the operators 'and' and 'not'.
Added support for tile rotation

Extends tile flipping with clockwise and counter-clockwise rotation by
increments of 90 degrees.

To support rotation, renderers need to handle the new FlippedDiagonally
GID flag.

Adds new keyboard shortcuts 'Z' and 'Shift-Z' for brush rotation.

Closes #19
Fixes to tile rotation related to oversized tiles

Tiled has specific handling of oversized tiles that was not taken into
account in the tile rotation patch. Tiles that are larger than the map
grid stick out at the top and right of a tile. This affects the
rendering code as well as the code that keeps track of the maximum tile
size used on a layer (in order to determine the area to repaint when
tiles are changed).

Also 'Left' and 'Right' are now used rather than 'CCW' and 'CW'. It's
shorter and should be clear enough.
Delete .command files after use on mac
Cleanup in make-dist-mac.sh

- Remove CONFIG += x86 comment due to Qt mac frameworks not having 32 bit code
- Autodetect plugins using ls
- Better output
Added a compile option to pass version information

This lets you modify the version of Tiled within the building process.
This is useful for daily builds.

The lines below show how to pass useful version information to the build
process:

  commit = $(git describe)
  qmake "QMAKE_CXXFLAGS+=-DBUILD_INFO_VERSION=$commit" -r
  make
Merge branch '0.7'
Fixed missing parenthesis
Improved handling of many tilesets

The tab bar is discarded for a drop down. Toolbar added for import,
export, tileset properties, and delete tileset. These entries are
removed from the context menu on TilesetView. MapDocument gains a proxy
for setting Tileset filenames and emits a signal on a change.

Handy button provided to get after tileset->setName(). Drop down is
uneditable between edit requests to assist switching the active tileset.
Tilesets are sorted alphabetically in the drop down.
More improvements to tileset handling

* Tileset renames now have undo functionality.
* TilesetDock caches the selected tileset between document changes.
Some code cleanups

* Renamed UndoTilesetName to RenameTileset
* Renamed UndoSetTilesetFileName to SetTilesetFileName
* Renamed setTilesetFilename to setTilesetFileName
* Renamed tilesetFilenameChanged to tilesetFileNameChanged
* Introduced TilesetDock::currentTileset helper function
* Changed the label of the Rename button from '...' to 'Rename'
* Removed two duplicate lines
Made the 'Show Grid' option in the tileset view persistent

Apart from being persistent, it now also applies immediately to all
tileset views.
Removed the no longer used mSelectedObjectGroupItem from MapScene

Basically AbstractObjectTool took over the job of keeping track of the
currently selected object group.
Introduced an option to highlight the current layer

The highlighting works by darkening the layers below the current layer
and making the layers above the current layer more transparent.

This mode should help to make it clear which layer you're editing and
also serves well for checking a map for errors. The mode can be toggled
by pressing 'H'.

The degree of darkening or transparency is currently not configurable.
Highlighting the current layer should be off by default
Small layout improvements to the Tilesets dock
Fixed tileset dock buttons to be disabled when appropriate

The buttons were not correctly disabled on startup. Also, crashes are
now avoided when somehow the actions do get triggered.

Thanks to @cjwillcock for spotting this regression and providing the
initial patch on which this one is based!
libtiled-java: Some small code cleanups

Removed redundant casts and use shorter for loops where possible.
Added zlib1g-dev to the dependencies for building on Ubuntu/Debian

This package is required for using zlib directly.
Avoid creating multiple polygon points at the same location

When creating a polygon or polyline, it was easy to end up with multiple
points placed at the same location. Since this is basically never
intended, additional clicks on the same location will now be ignored.

Thanks to @Aranda for pointing out this issue and suggesting this fix.