Merge pull request #8 from choonkeat/master

Add button_html and button_class options for "flash_messages"
Merge pull request #9 from choonkeat/master

Fix #winston/rails_utils/7 do not render flash[:timedout]
Upgrade to ruby 2.1.4.
Update to 3.3.0 and update docs.
Merge pull request #10 from choonkeat/master

`page_title` should prefer to use `:default` provided by gem user
Version bump.
Add proper "at_least_one" validation for managing "Parent has_many :children"
- "marked_for_destruction" is needed to catch "accepts_nested_attributes_for allow_destroy: true"