Fixed typo in the German translation
Added Russian translation
Added a command line option to disable OpenGL

OpenGL drivers can still have their problems, especially on Linux but also when
running Windows inside VirtualBox. This option allows for recovering from
enabling hardware accelerated rendering and not being able to start Tiled
anymore.
Added more file patterns to .gitignore

Most of these are probably generated when compiling with Visual Studio.
Solved the zlib dependency problems on Windows by inluding the headers

Now Tiled should compile out of the box with either MinGW or the
Visual Studio compiler.
Merge branch '0.7'
Fixed a crash that could happen when removing the current layer

The current-layer highlighting code assumes the MapScene is up to date
with the layer stack of its MapDocument, but when dealing with a current
layer index changed signal this wasn't always the case.
Attempt to avoid the History view related crash

Always show the vertical scroll bar in the History view, in an attempt
to avoid the QListView crash that happens due to infinite recursion in
some layout/geometry code.

A variation of QTBUG-14412 seems to be still around even in Qt 4.8...
Introduced string conversion functions for Map::Orientation

Almost every map reader and writer will have to deal with converting the
map orientation from and to a string. Duplicating that code makes it
cumbersome to add new orientations.

In the process removed the Hexagonal enumerator since it makes no sense
to keep that as long as there is no support for hexagonal maps yet.
Added forgotten export declarations that are needed on Windows

Fixes undefined reference errors when linking Tiled and its plugins to
libtiled.
Mentioned the Russian translator in the AUTHORS file
Replaced the Random Mode icon with dices

The icon is based on the SVG by Steaphan Greene found here:
http://en.wikipedia.org/wiki/File:2-Dice-Icon.svg

I adjusted the line width and dots for the small size and added some
shading.
Updated the translation files to the current sources

The translations now contain a total of 422 source texts, out of which
108 are new since 0.7 (though about 30 of those seem to have either
moved or changed just a little, if I understand lupdate correctly).

This commit marks the string freeze for the 0.8 release.
Removed the now unused random clone tool icon

Was replaced by the dice icon in commit bf164cc4841fcc84143e85d3.
Updated the Russian translation
Updated the German translation
Fixed segmentation fault in stamp brush random mode

Tiled crashed when right-click dragging an empty area and then trying to
paint with Random Mode enabled.

Since no random tile could be selected, brushItem()->tileLayer() ended up
as NULL, but when painting it was used unconditionally (the mStamp was
checked, but that is no longer the tile layer used for painting).

The check whether the stamp is outside the map was corrected as well.
Update all objects in a group when changing the group color

Since recently the object color is cached in the MapObjectItem class, so
we need to emit the objectsChanged signal rather than just asking for a
repaint.

Fixes #106
Updated the Japanese translation
Updated the Spanish translation