Map renderer resources management refactor
Fix lost TODOs
Fix build
Fix build
Fix build
Fix build
Fix build
Fix build
Fix build
Tidy-up MapRenderer ctor
Make EXT_shader_texture_lod optional
Fix GLES2
Revert "Fix GLES2"

This reverts commit 6c6e1954271b840850690093aa0c7456640d2a70.
Make GL_EXT_shader_texture_lod conditionally required