Ghostscript.NET 1.1.1

Fixed problem in the GhostscriptRasterizer and GhostscriptViewer when MediaBox contains negative llx or lly values. (problem reported by "Prasenjit Das"). Added GhostscriptPngDevice, a friendly output device class with all png devices related switches. (GhostscriptPngDevice supports: png16m, pngalpha, pnggray, png256, png16, pngmono, pngmonod). Added GhostscriptJpegDevice, a friendly output device class with all jpeg devices related switches. (GhostscriptJpegDevice supports: jpeg, jpeggray). Extended GhostscriptProcessor.StartProcessing method to support GhostscriptDevice base class as StartProcessing parameter. For each constructor / method that requires GhostscriptVersionInfo parameter, now there is one more constructor / method available with a same functionality but without a need to pass GhostscriptVersionInfo parameter. This new constructors and methods automatically retrieves and use last installed Ghostscript version. Added new samples to the Ghostscript.NET.Samples project (AddWatermarkSample, ProcessorSample, DeviceUsageSample).