Epub3 Fixed Layout : Fix properties extraction
Extract current spec version of Epubs
Epub 3.0: Extract chapters from navigation document

http://idpf.org/epub/30/spec/epub30-contentdocs.html#sec-xhtml-nav
Fix xpath query for nav document path
Merge pull request #13 from klacointe/epub3_fixed_layout

Epub 3.0 : Reading compatibility
Don't obscure Zip::Archive#read by overriding.
Version bump to 1.1.2.
Fix for rebase mistake, version bump to 1.1.4.
Add epub3 page-progression-direction attribute
Remove warning about URI.unescape
Fix test_generate_component
Fix some more warnings
Epub3 Fixed Layout: spine itemref elements
Merge pull request #14 from nono/epub3_fixed_layout

Further EPUB3 support

* component fixed layout properties
* book page progression direction

Plus fixes for several warnings under Ruby 1.9.
Format properties.

Some ebooks have instructions about how they should be displayed. These are now
captured in a new book array of `format_properties`.

They include:
- source format name (`source`)
- source format version (`version`)
- direction that the text should flow (`page-progression-direction`)
OCF, OPF, NCX, NAV, etc - called 'blueprints' here - are first-class citizens.
Version bump to 1.2.0.
Version bump to 1.2.1 because rubygems.org lost the file.
Switching to the CGI library for unescaping URIs.

Here's a good explanation of the reason:

    https://github.com/seancribbs/webmachine-ruby/issues/15
Version bump to 1.2.2.