Updated to latest ZXing.Net source (2014-03-21)
Added some platform checking code for android to detect if we have the right permissions, etc, also added a performance counter helper class
No more auto-rotate always.  The scanner now rotates how it needs to given the orientation, plus we're not using YuvImage anymore, so memory usage and speed should be greatly improved for decoding barcodes.
Manually added Cheesebaron's fixes for resuming fragment which closes #93
Manually brought in @Cheesebaron fix for Windows Phone preview sometimes not starting...
Manually merged fix for #71