Update jquery.are-you-sure.js

Implemented change as discussed here: https://github.com/codedance/jquery.AreYouSure/pull/47
Merge pull request #50 from valgen/patch-1

Merged in change from valgen to address #47.  

TODO:  Do some cross browser testing and ensure no NPE under selected conditions
Create composer.json
Address null/empty select/option field handling

* Reverted the getValue select field handling back to pre 1.7 logic.
Multiple issues have been reported and many of the proposed fixes had
issues with older versions of jquery.  1.7 logic worked so let's revert
for now.

Closes #55
Updated version references and README for v 1.9
Update composer.json
Merge pull request #58 from nicolas-brousse/patch-1

Create composer.json