chore(*): remove dead code

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
doc(doc/lua): add constant and function application API documentation

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
doc(doc/lua): add variable and lambda abstraction API documentation

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
doc(doc/lua): add variable and lambda abstraction API documentation