Add offset support

Add offset option

- Can set the height offset to display below another element fixed to the page, like a sticky header
- Update readme examples
- Bump version

Fix Firefox support

Fix #3

- Fix support for Firefox
- Add bower

1.1.2

• Add a check for if the browser supports transition
• Change some defaults and update the readme accordingly

Add events

Add various events:

• sticky-created
• sticky-update
• sticky-hit-top
• sticky-hit-bottom
• sticky-frozen
• sticky-unfrozen

1.0.0: Act on container height changes

• Replace usage of jQuery functions to native functions
• Use single ticks instead of mixed double quotes and ticks
• Change the throw error to a console.error
• Add a setInterval that checks each sticky instance's container height to see if it changed and needs to have it's boundaries updated
• Add CSS animation option
• Document methods and options better
• Add minified file
• Remove useFixed entirely, only relies on relative positioning now