Timing of 'chosen:showing_dropdown' fixed

Currently the event is triggered before dropdown LI's
are created. This commit corrects it by moving the
trigger event at end of method. A JSFIDDLE was created
to demonstrate the issue.

http://jsfiddle.net/lagrz/3A5jq/

By moving the event it enables developers to add
whatever additional code or styling to the dropdown
menu options such as images.
Fire the `chosen:showing_dropdown` event only after results
are totally built.

Further information about this fix is described in:
3246598cbb93b66026828ab85754c65378f43ea9
add support for cut/paste events

A short delay (currently 50ms) is required after the paste event for the
pasted text to enter the textbox.  Then we can trigger a `keyup` event as if
that copy had just been typed into the box manually.
Change `search_text` to use `option.text` rather than `option.html`
Support jQuery < 1.6 by not using $.fn.is().

Adapted from rooby's pull request for issue #1555.
Merge pull request #1702 from opensourcery/master

Remove use of `$.fn.is()` in favor of more widely supported methods.
trigger "chosen:no_results" event, with second arguments added
make sprite vars default to be able to preset outside of chosen
Merge pull request #1736 from benib/sprite-vars-default

make sprite vars default to be able to preset outside of chosen
Add note that Chosen is disabled on mobile
Remove linear-gradient from single chosen input background
Merge pull request #1744 from harvesthq/remove-input-linear-gradient

Remove linear-gradient from single chosen input background
Fix closing selects in pop out windows by moving document event bindings to the container's ownerDocument.
Merge pull request #1745 from mickylad/bind-events-to-owner-document

Fix closing selects in pop out windows by moving document event bindings...
Slightly more accurate copy
Merge pull request #1741 from harvesthq/chosen_on_mobile_docs

Add note that Chosen is disabled on mobile
Merge pull request #1603 from daveworth/1601/support_paste_events

Add support for paste events
Merge pull request #1478 from harvesthq/change-list-showing-event-order

Trigger/Fire Results Showing Event After Winnow
Merge pull request #1712 from lightxu/patch-1

Empty search triggers "chosen:no_results" event
Add documentation for the chosen:no_results event