Fix pixel coordinate to tile coordinate conversion

This addresses issue #9. Although this does not appear to be an issue on Linux
for some reason, it affected a Windows build and the logic appears sound e.g `50
/ 100` correctly resolves to tile `0` whereas `ceil(50.0 / 100)` resolves to
tile `1`.
Merge branch 'master' of github.com:geo-data/cesium-terrain-builder
Update CMake rules in order to generate Visual Studio 2013 solution without issues. This means disable all non-workable checks (CXX11, CXX0X and unified GDAL) and remove compilation debug flags.
Add CPL_DLL to ctb class declarations and CPL_DISABLE_DLL to CMake preprocessor definitions in order to handle DLL export/import of ctb.

Add GDAL include directories to tool project builds in CMake rules.
Add CPL_STDCALL on some static methods. Without this macro project not compile.