Activated TrueType width calculator

The TrueType width calculator was essentially unused, and was being set
to TypeOneOrThree width calculator, upon activating it, found an error,
I fixed that as well.
remove debugging output
Merge branch 'use-truetype-calc'
move page orientation detection into a dedicated class

* significantly easier to unit test
remove some unused spec PDFs
reduce the whitespace changes to integrity.yml
use a context block to make these spec lines < 100 chars

* so that the quality specs continue to pass on this branch
Merge branch 'page-orientation'
add point from Page#orientation specs to PageOrientation unit specs
the MediaBox might be an indirect object

* fixes #91
ensure we can decrypt PDFs with no ID

* the PDF spec says encrypted files MUST have a document ID
* Yet Acrobat reader works just fine when they don't so let's copy their
  behaviour
uses Digest::MD5::hexdigest instead of md5sum
forced UTF-8 encoding of md5 for integrity_yaml
Revert "forced UTF-8 encoding of md5 for integrity_yaml"

This reverts commit dedeec20f677c3442b9a089c3bc3bd6f655f90af.
Merge branch 'md5-compatability'
gracefully handle built in fonts that include control char glyphs
raise a MalformedPDFError instead of ArgumentError

* according to the contract specified in our README, ArgumentError isn't
  allowed to bubble up
add an integration spec for times control char glyphs

* we shouldn't raise an exception when a PDF uses the built in
  times-roman font and includes a control character glyph
reset LZW code width on CODE_CLEAR_TABLE
tweak this spec so it passes on rubinius