Add qtcreator/build.ninja and rules.ninja to .gitignore.
Makefile cleanup.
- Print set option values in cmake_options block.
- Kill CLANG_ANALYZE. Use scan-build.
- Add CLANG_ANALYZER_NORETURN to vogl_assert() and vogl_fail().
  Scan-build markup.
Enable Wshadow
- Lots of shadowed variable warnings.
- Several look like real bugs.