Version 1.2 for Symphony 2.3.3+

Makes this extension fully compatible with Symphony 2.3.3+ and includes the following changes:

 1) Removing file path from file name (according to https://github.com/symphonycms/symphony-2/issues/1719)
 2) Added update-function to perform the needed file path changes in the database.
 3) Changed deprecated pass-by-reference arguments to pass-by-value arguments (PHP 5.3+) (Fixes https://github.com/TwistedInteractive/reflecteduploadfield/issues/4)
 4) Updated Readme and Meta.