3D rendering : first stage
Small renderer refactor
Add distance control using mouse scroll wheel
debug tiles rendering
Some fixes to positioning
Map tile provider concept
Qt event loop, threaded downloading of tiles
Online tile provider queue
GLEW in Core
Need to implement texture unloading
New feature introduction: tile atlases
Remove textures only in render thread
Forbit caching tiles into textures from other threads then render one
Allow tiles from atlases to be 'freed'
Tile URL forming bug fix
Skip obtaining tiles that are already pending
Fix UV coordinates. Need to change cache organization
TileId common type, TileZoomCache class
Fix for thread conflict, fix of tiles downloading queue
Refactor 3D render configuration