Alias support ... review request

[Mark Lentczner]

I've got alias support pretty much done. Pull request, if anyone would like to code review before I commit to main: https://github.com/mzero/plush/pull/19

The aliases.doctest file is full of some hilarity of how aliases work.

Still left to do is: Aliases throw all the annotations off as the character positioning information is wrong (it is post-aliasing, but the user sees the unaliased command line), and there is no annotation information on the aliasing itself. I should have both of these done tonight in another change set.

- Mark

[Mark Lentczner]

I updated this code a bit - and rebased, so here is a new pull request for it: https://github.com/mzero/plush/pull/20   -- code reviews welcome before I commit to master (tomorrow evening?)

- Mark