[plugin-media] Record Audio fails on windows platform

1. Create mobilespec app witn windows platform
2. Run plugin manual test ->org.apache.cordova.media.tests.tests
3. Press Record Audio 10 sec - at wp8.1 get error: recordAudio(): Audio Error: undefined
4. Status don't changes to Stopped when finished recording
5. Press play - nothing happened

Exception was thrown at line 54, column 5 in ms-appx://org.apache.mobilespec/www/plugins/org.apache.cordova.test-framework/www/medic.js

0x800c0005 - JavaScript runtime error: The system cannot locate the resource specified.

Issue is that Media plugin for windows treats src property of Media instance as a file name inside of Music library, although it can be a full path to file.

Solution is to record audio file to temporary folder, and if full path for file is provided, copy recorded file to this path, otherwise, leave recorded file at temporary folder.

Also it is necessary to update tests to properly handle windows specifics.