Removing char* assignments from headers

In case if your application, which includes Marble headers, also
define QT_NO_CAST_ASCII, it won't get built. For instance,
KF5 use QT_NO_CAST_ASCII by default, so we should use
QLatin1String, instead of char* in all public headers.

REVIEW: 121487
Remove unnecessary slot and tabstop.
REVIEW:121531
Fixing UI-related issues in Weather plugin

Patch takes care of broken degree symbol in WeatherItem and
invalid weather condition icon for N/A conditions

REVIEW: 121528
introduce MarbleView
introduce MarbleGLView
introcude GlLayerInterface
clear depth buffer between layer rendering
TextureLayer
PlacemarkLayer
introduce triangulation algorithm for polygons

* taken from http://www.crystalspace3d.org/svnroot/crystal/CS/trunk/{include/csgeom/triangulate.h, libs/csgeom/triangulate.cpp}.
GeometryLayer
introduce GeoGraphicsScene::GlTile and use glDrawElements
adapt PlacemarkLayout
use shaders
GLRenderer
cosmetics
attributes--
split matrices in texture vertex shader
wip projection in shaders