Fix filestructure_unittest

This patch is ugly (sorry).

The commit messages detail the important changes:
```
commit a376d2380475653fb7544687b1ef5bcf99aa7dd5
Author: Caitlin Potter <snowball@defpixel.com>
Date:   Fri Apr 5 12:33:31 2013 -0400

    Fix filestructure_unittest
    
    Carefully ensure that lines and columns are being adjusted correctly
    (except that multibyte characters still occupy multiple columns, will
    correct in future).
    
    Renamed missing-cue-identifier.vtt (This file is actually missing
    cue-times, not a cue identifier).
    
    Made line/column for incomplete cues relatively expected value (But
    honestly I'm not sure what the best way to do this is, and the way it
    is now is probably wrong)
    
    Removed the *mode parameter from read_cuetext() and parse_webvtt(),
    because this always points to self->mode anyways. Updated
    readcuetext_unittest to accomodate this.
    
    Removed duplicate test (MultiCueNoNewlineBetweenCues and
    MissingNewLineBetweenCues are testing the same thing, so the latter
    was removed)

commit b35534e1468373145d10f9feee3f205622bc01ae
Author: Caitlin Potter <snowball@defpixel.com>
Date:   Fri Apr 5 13:00:28 2013 -0400

    FileParser::parse() no longer returns false when status==UNFINISHED
    
    The mechanics of this are pretty iffy :( Originally I was saying it
    would be a failure if either statuses were not WEBVTT_SUCCESS
    (finish_parsing pretty much always returns WEBVTT_SUCCESS, so a parse
    failure would still return 'true' when using the same variable.)
    
    I've "fixed" this by setting status to WEBVTT_SUCCESS if it is equal
    to WEBVTT_UNFINISHED.
    
    There's probably a better way.
```