Refactoring: added Guide and Spine classes, begun work on __init__ rewrite.
Refactoring: added Guide and Spine classes, begun work on __init__ rewrite.
Added tests
Completed Spine class, optimized manifest-link subroutine
Corrected Spine class
Redone file.write and file.close
New tests: metadata dict and content
Radical refactoring
Extended test coverage
Refactor: factory EPUB
Bugfix in append mode.
Bugfixes: return null on empty ncx