1.2.0-Leia

• Complete rewrite to support GL again
• Add glm on depends for GL matrix calculation
• Add Kodi's GL header (already on Matrix, but not on Leia)
• Remove all old shaders where not supported on Windows
• Add pure GL/GLES shaders to own path
• Change cmake GL/GLES lib find way
• Change -fPIC to use of POSITION_INDEPENDENT_CODE on cmake parts
• Update CMakeLists.txt to 3.5
• Build with Kodi Leia API