Version 1.1.0 release candidate 1

Release candidate for version 1.1.0.

What's New:

• Added a ProMotion executable called promotion. You can type promotion new <myapp> and it will create a ProMotion-specific app. We will be adding more functionality in the future.
• Can now pass a symbol to add, add_to, and set_attributes to call a method with that name to get styles.
• Added button_title: to open_split_screen to customize the auto-generated button title
• Updates to set_tab_bar_button
• Added to PM::Delegate on_open_url(args = {}) where args contains :url, :source_app, and :annotation
• Added to PM::Delegate tint_color to customize the application-wide tint color
• Added to PM::MapScreen annotations the ability to set an image
• Removed legacy navigation_controller references which were causing confusion.
• Allowed setting a custom_view for bar_button_items.
• Added will_begin_search and will_end_search callbacks to PM::TableScreen.
• Added title_view and title_view_height to sections in PM::TableScreen.
• Updated screenshots for iOS 7
• Refactored code and lots of new passing tests