GitLab

It's more than likely that there's some logic errors lurking in here.
Very likely. Of utmost likelihood.

Fixes #4.

This also introduces globals optind and optarg.

For options a, b, and c where c has an argument:
* "-ab" will parse as a, b
* "-abc d" will parse as a, b, c=d
* "-abcd" will parse as a, b, c=d
* "-cdba" will parse as c=dba
* "-- -abc" will parse as (nothing)

All arguments will be reordered properly such that non-parameter
arguments are at the end of argv.

Fixes #2.

* Delete junctions & directory symlinks
* Delete all sorts of files
* Do not delete directories
* Allow symlinks (only) against nonexistent targets -- assume they are
  files

Fixes #1.

Fixes #3.