Add batch operations (delete, tag) for bookmarks/tags. Fixes #235
Don't allow selection of invalid items in bookmark/tag CAB mode(like bookmark headers and last page).
Fix tagging single bookmark not showing the currently applied tags.
Safeguard against array index out of bounds crash when getting invalid "last page".
Currently just logs a warn, but ideally we should find the root cause of why an invalid page number is saved.
Merge pull request #237 from afarra/master

Add batch operations for tagging/deleting bookmarks & tags