default to first slide instead of last.

The named anchors patch I merged had a flaw in how it merged slide
numbers and names.
Fix dependencies and add nicer usage messaging
update changelog
Merge pull request #148 from binford2k/ticket/146/default_to_first_slide

default to first slide instead of last.
Merge pull request #149 from binford2k/ticket/122/workaround_upstream_dep_bug

Fix dependencies and add nicer usage messaging