jckarter/clay — pull request #433 by stepancheg (2012-10-23 21:11:12+00:00)
Title: define private overload

Declaration like:

```
define foo private overload;
```

can be overloaded only within same module. `define private overload`
increases code readbility: reader quickly understands that declaration
is not overloaded elsewhere causing unexpected effects.

Patch adds `module` field to `TopLevelItem`, although right now
module is needed only in `Procedure` and `Overload`.

First patch is minor refactoring.

Third patch adds some private overloads to the standard library.