Update Scala lexer to output more differentiated token types.

[alanqthomas]

Motivation

I decided to write this lexer addition because I felt the tokens being output by the current Scala lexer implementation were too general, usually a Name token. This PR makes the lexer output some more specific token types. This allows the stylesheet to define more specific colors for different tokens while also leaving it open to having these new token types be styled the same way as before.

New Token Types

• Name::Function for def names
• Name::Variable for val names
• Name::Property for anything used after a . e.g. method calls, class fields. I chose Name::Property because calling vals or defs on an instance are more or less interchangeable
• Name::Function for def/function calls

Before:

After:

[pyrmont]

This looks like a nice improvement! Thanks for taking the time to add it and sorry for the delay in getting to the PR. Just one comment below: