Some tweaks following Steve's testings

[jdunkerley]

Pull Request Description

• Add ranged number widget to at and get.
• Add defaults to at and get picking the first item.
• PRIVATE on various Excel_Workbook methods. It still works like a connection but not shown in CB.

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• The documentation has been updated, if necessary.
• Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• All code follows the
  Scala,
  Java,
  TypeScript,
  and
  Rust
  style guides. In case you are using a language not listed above, follow the Rust style guide.
• Unit tests have been written where possible.

[GregoryTravis]

What does this change do? Naively, I thought self.at == x-> self.at x == self.at _.

[radeusgd]

Once the index argument of at got a default, calling self.at will force all default arguments and thus will return the first element, not the lambda. The equation above holds if there are no default arguments.

Btw.

Suggested change

	proxy = Array_Proxy.new self.length (self.at _)
	proxy = Array_Proxy.new self.length (self.at ...)

would probably work as well