Fix Perl module completions.

This fixes the issue with nonexistant directories (some Linux
distributions put these for local modules), and also fixes the
issue of dot meaning any character instead of simply dot.
web_config: update AngularJS to 1.0.8
abbr.fish: add abbr, a command to manipulate abbreviations

Work on #731.
web_config: set width to dynamic 80% of window

As we add more tabs, 800px looks increasingly cramped, and our config
should take advantage of the screen space available.
web_config: add support for viewing abbreviations

Add a new tab which lists the current abbreviations defined, by wrapping
the `abbr` command.

Work on #731.