Gather some data about the heightmaps, and pre-convert them doubles instead of doing it every single bloody time they're used.
Merge branch 'master' of https://github.com/pioneerspacesim/pioneer into UnifyHMaps
Merge branch 'master' of https://github.com/pioneerspacesim/pioneer into UnifyHMaps
This is a noisey commit due to a few const changes.
The actual meat of it is a new TerrainColorEarthLikeHeightmapped.cpp file which splits the heightmap using branches out of TerrainColorEarthLike.cpp and simplifies them both in due course.
Also TerrainColorTFPoor.cpp no longer has the heightmap branches since IT NEVER USED THEM.
Assert and const again.
Assert bounds check and if null checking.
Merge branch 'master' of https://github.com/pioneerspacesim/pioneer into UnifyHMaps

Conflicts:
	src/TerrainBody.cpp
Try to tidy up the eclipse shaders so they're a little more GLSL120 compliant in the hope that it'll make Tichy's open source AMD driver work. Totally blind.
Damn this is complicated.
Merge branch 'master' of git://github.com/pioneerspacesim/pioneer into simplfyEclipse
Just pick from the matrix rather than doing if tests
Pre-divide srad and lrad, pass them through as a uniform.
Pass the inverse (??? i.e. 1.0 / NUM_LIGHTS) value through as a #define to the shader to avoid calculating it per fragment. Means I can avoid two divides within some nested loops.
Oops, fix that last commit!
split shadowCentre into vectors of components
fix bad bracketing in atmos eclipse shader
apply eclipses to sunsets
Merge branch 'master' of git://github.com/pioneerspacesim/pioneer into simplfyEclipse

Conflicts:
	src/graphics/gl2/GeoSphereMaterial.cpp
Make the RenderData const, where required to change it for the blend masks use a copy.
SpaceStation.cpp - don't render the city OR the station if we're too far away.
ModelBody.cpp - reserve the vector for the number of lights.
CityOnPlanet.h/cpp - Remove the per building enabled flag, instead keep a list of the enabled buildings and only draw those. Also add a city wide m_clipRadius flag and test the whole city before trying to render buildings.
Reduce the amount of work the CityOnPlanet::Render method is doing per building.