Play with extensions (refs #118)
Add loading of extensions to glow init (refs #118)
Merge branch 'master' into extensions_registry
Merge branch 'master' into extensions_registry
Merge branch 'master' into extensions_registry
Add cmake option to generate constants and extensions
Merge branch 'extensions_registry' of github.com:hpicgs/glow into extensions_registry
Fix cmake prebuild step
Integrate Extension checks (refs #118)
Move global functions to global
Fix extension check usage test (refs #118)
Merge pull request #123 from hpicgs/extensions_registry

Extension availability checks