Add build-in api cache.
Fix one potential issue with cache
'requestHandler' expose now XMLHttpRequest.
Merge branch 'master' of github.com:prismicio/javascript-kit into api-cache

Conflicts:
	dist/prismic.io.min.js
Merge pull request #40 from prismicio/api-cache

Add build-in api cache.
Update README.md with typical syntax
Add support for XDomainRequest (support legacy IE)
Merge pull request #46 from guillaumebort/master

Add support for XDomainRequest (support legacy IE)
Merge with current master
Merge pull request #47 from srenault/master

Merge with current master
Got status "Aborted" every time prismic was queried in IE9. According to the article at http://cypressnorth.com/programming/internet-explorer-aborting-ajax-requests-fixed/ requests sometimes times out in IE. The solution was to wrap the xdr.send() in a setTimeout function.
The wrapping of xdr.send() in a timeout function has caused problem for some. Changed it to the other solution where the ontimeout and onprogress callbacks are present. Also changed the reject method to take a msg parameter since the function is also used when a timeout occurs
Dist files reset
Merge pull request #48 from karmats/ie-fix

Fix so that IE doesn't abort requests to prismic