Releases for Book helper

• Issue #2275029 by ydahi, ram4nd: hook_permission() typo since porting from D6.
• Issue #2344123 by kurkuma: Book (inline) navigation not working when cache for blocks enabled.
• Remove excess variable.
• Issue #1813606 by bleen18: Undefined index: module in book_helper_menu_link_alter()
• Issue #1809342 by jrockowitz: array_diff() Error
• #1776208 - Misspelling in UI text

Changes since 6.x-1.0-beta1:

First beta release of the book helper module.