Implement named scopes

[jespa007]

It will let it declare variables in other scopes.

my_space{
   var my_var_in_my_space=10
   ...
   my_space2{
         var my_var_in_my_space2=10
         ...
  }
}

the access of my_space will be my_var_in_my_space_scope::l

Also in the classes constant variables can be treated as namespace,

class A{
    const MAX_COUNT=10;

}

The access is like A::MAX_COUNT

In the 2.0.0 it was supported but with a patch