remove ReVIEW.book

ReVIEW.book is used as global variable.
In *builder, @book is better than ReVIEW.book.
(It should be used in initialization and tests)
variable name for OptionParser object should be 'opts', not 'parser'.
Merge branch 'dmiyakawa-test1'
Merge pull request #290 from takahashim/remove-review-book

remove ReVIEW.book
Merge remote-tracking branch 'origin/master'