Angular Ui Tour Versions Save

Fixes #159

This is a huge milestone for this project! Without being dependent on AUIB, Angular UI Tour will have more control over timing and positioning of the popovers, and no longer break when AUIB releases big changes. It also means that AUIB is no longer needed, only Bootstrap 3 (and very soon, Bootstrap 4) styles!

Angular UI Tour now only supports Angular Bootstrap 2.x.

This is the last release the supports Angular UI Bootstrap 1.x.

Added or enhanced the following features:

• Updated the documentation with missing or inacurate information and best practices
• Created a better "backdrop" the allows interaction with the content of the target element
• Added the "scrollIntoView" options that configures whether or not the tour scrolls after a step is shown
• Merged @diego-vieira's PR that adds the "useHotkeys" option, allowing the tour to be controlled with the keyboard
• Added UI Router integration
• Multiple tours

This pre-release is for the authors of multiple issues to test the fixes that I made.

Added or enhanced the following features:

• Updated the documentation with missing or inacurate information and best practices
• Created a better "backdrop" the allows interaction with the content of the target element
• Added the "scrollIntoView" options that configures whether or not the tour scrolls after a step is shown
• Merged @diego-vieira's PR that adds the "useHotkeys" option, allowing the tour to be controlled with the keyboard
• Added UI Router integration

In 0.4.0 the tour itself has become an event emitter (see README for details). Also started exposing the current step (as a copy of the step) and the tour status (on, paused, off).

Special thanks to @dander401 and @cesarcosta99 for helping identify and debug a handful of issues.

Fixed #13 and #16.

Added a service for retrieving references to tours. See documentation.

Also, added tests and cleaned up source code.

All public tour API methods now return promises. Also added documentation for each method. Added new method that allows jumping to an arbitrary step.