feat(util/name): add optional<name> helper functions for implementing Lua API

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(library/expr_lt): add expr_quick_cmp functional object

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(library/kernel_bindings): add to_io_state_ext helper function

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
refactor(library): add module namespace

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(library): add support for creating 'private/hidden' names

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