chore(lua): rename init_* functions to open_*

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(lua): expose options object in the Lua bindings

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
fix(lua): problem when compiling with clang++

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>