Tab vs. Space Indents Final Decision (Version 3.0)

At the risk of seeming like an indecisive leader, I'm going to change the
indent decision.

We will allow either space or tab based indents, but not in the same file.
This idea was pitched by several people and I think it is a compromise worth
trying.

The lexer will take the first indent it finds and record it.  If it is a
group of spaces it will record that and record the number of spaces.  From
then on every indent must be a matching tab or space group of equal length,
or a lexer exception will be thrown.

This will still allow the auto-continuation scheme to work, since all
indents must be one tab or an equal number of spaces.

We will announce when a build is released with this feature.