Adding support for creating Atoms in expressions

[jdunkerley]

Pull Request Description

• Enables the .. autoscoping style for creating Atoms in expressions.
• Add type checking to methods in columns.
• Auto wrap returns from method in expressions into a column as needed.
• Remove Time_Period.Day to remove confusion..

Important Notes

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.

[Akirathan]

Java changes OK. Please, don't forget to add tests for the new syntax in expressions, I have not seen them in your PR yet.