Added click to select files support
Ignore other drops, instead of error
Add file param to URL function call

Add a file param to the URL funciton call so we can switch based
on the file's properties.
Added file extension constraints.
Update README.md with allowedfileextensions example
Added error example for FileExtensionNotAllowed
file to files[fileIndex]
allowedextension typo
Fix loops
Fixes cases where an empty opts.data results in params containing a single empty string,
causing "undefined" to show up in the post body, eg:

--------multipartformboundary1361198653141
Content-Disposition: form-data; name=""

undefined
using readAsText if no readAsBinaryString

This works for text files in IE10.
use binary url
Minor fixes
moved "global" filedrop variables into closure scope

doc_leave_timer, stop_loop, files_count, files should not be global for
all filedrops - they cause weird bugs when there are more than one
filedrop element on page. For example shared doc_leave_timer causes
multiple docLeave triggering.
Guard against empty files
Issue with IE8. FileReader is not defined.
forced X-Requested-With
Add README syntax highlighting
added requestType to options
Update README.md to make better use of GitHub markdown.

And few minor edits.