Added option for modal-like popups

This adds three new options to enable modal-like behavior:

* showCloseBtn: Disables displaying the close button.
* enableEscapeKey: Disables dismissing popups by using the keyboard.
* modal: Enables modal behavior for a popup, so it's not dismissable by
    usual means. This is a synonym for setting closeOnContentClick,
    closeOnBgClick, showCloseBtn, and enableEscapeKey to false.
Fix typo in website code comment
Merge pull request #114 from johnbacon/patch-1

Fix typo in website code comment
added beforeClose event
ImageLoadComplete event
Remove jQuery event alias calls

We use a custom jQuery build withouth the event-alias module so functions "click" or "focus" are not working and calls to the underlying methods "on" and "trigger" should be used. Works like a charm now! :)
Merge pull request #130 from acasademont/patch-1

Remove jQuery event alias calls
Merge pull request #94 from julen/feature/modal

Added option for modal-like popups
Cleaned duplicates css
Merge pull request #133 from yannabgrall/master

Cleaned duplicates css
0.9.0
oops (readme upd)
Bugfix: incorrect event object when initialized from multiple elements
Click on image with command or ctrl key now opens it in new tab, instead of opening popup
removalDelay now only works if CSS transitions supported
Fix: cached image blinks on opening
Added solid bg to images, changed appearance of arrows
Added image zoom module
0.9.1, see changelog for details
zoom module fix