fixed bad inheritance handling of rendition properties
rendition properties inherited from package
missing rendition orientation accessor
Merge pull request #29 from readium/feature/rendition

spineItem inherits rendition properties from package
Fixed issue with fixed layout books initially openned in the single spread
fixed two-page spread automatic page turn
Merge remote-tracking branch 'origin/develop' into feature/prevNextPage

Conflicts:
	js/views/fixed_view.js