Added an option to disable building of the Python plugin

Having some issues with it on Mac OS X currently, which I'll look into
another time.
Fixed draw order for duplicated object layers
Allow creating empty tilesets and adding images later

Sponsored-by: Jamie Rocks
Updated the New Tileset dialog to reflect individual images option

The dialog now features a combo box where the user can choose between
creating a tileset based on a tileset image, or a tileset that is simply
a collection of images. The images still need to be added later using
the '+' button in the tileset toolbar.

The drawing offset is no longer configurable using this dialog. It can
be changed in the tileset properties instead.
Bumped version to 0.9.1 and updated NEWS file
Exclude two hidden files from releases

The license header file and the Travis CI configuration file are not
relevant in source releases.
Updated copyright year in Info.plist file
Fixed possible crash when resizing the map

When the 'mapChanged' signal arrived, it was only checking whether it
came from our current map document. In practice, it should always come
from our current map document, but what we need to check is whether the
current object is the map itself.

Also avoid another potential crash when objects change without having a
current context object.
Avoid relying on dynamic_cast in libtiled

It's not needed anymore since the layer type is stored now. This allows
libtiled to be used without RTTI.
A few minor Windows installer updates

* Allow specifying a build directory separate from the repository root
* Take the compiled translations from the build directory
* Install LICENSE.APACHE.txt, which covers one of the plugins
* Don't try to delete no longer existing LICENSE.LGPL.txt
* Commented out MinGW dlls since I'm using VS 2010 Express now
Merge branch '0.9'
Avoid crash on quit while editing a property

Could end up referencing a null-pointer.
Final update to the NEWS file for 0.9.1 release
Added manpage for automappingconverter
Small fixes to the automappingconverter man page
Moved the layer format setting to the 'New Map' dialog

This should avoid confusion about the setting in the preferences not
taking effect and make it clear that it is a map setting now.

This change is jumping through some hoops to avoid breaking string
freeze, hence the use of QCoreApplication::translate.

Closes #447
Added extra zoom levels (both in and out)

Now it zooms from 1% to 25600% (going over than 400%, it uses GIMP's
pattern).

Closes #456
Merge branch '0.9'

Conflicts:
	src/tiled/mappropertiesdialog.cpp
	src/tiled/newmapdialog.cpp
Added a submenu showing all views and toolbars

It's actually the standard popup menu provided by the QMainWindow. It
will always include all dock widgets and toolbars added to the main
window, which is exactly what we want.

Closes #476