Added Base64 Image Encoder / Decoder (#951)
* Added Base64 Image Encoder / Decoder
* Fixed Linux build
* Fixed Mac build
* UIImageViewer can now render SVG
* Fixed View and Copy button in ImageViewer for SVG files
* Added unit tests and command line tool for Base64 Image Encoder / Decoder
* Updated JSON <> Yaml Converter and Base64 Encoder / Decoder command line tools
