CS-Script 3.21.1

# Release v3.21.1.0 * Added support for C#6 syntax to Mono evaluator. * Issue #33: Cleanup routine throws ArgumentException * Added extending environment variables in all parameters passed from command line. * Improved API XML documentation to address some of the Issue #26 concerns. * User experience improvements triggered by intensive Linux testing * Various improvements for stdout help. * Improved reliability of Auto-class decorating algorithm * Added support for referencing NuGet packages from the script being executed on Linux * Added -noconfig:print and -precompiler:print options for printing the content in stdout. * Extended Python-like "print" functionality: * Added params concatenation: `print(obj1, obj2,...objN)` * Added pringf for params formatting: `printf("Now: {0}", DateTime.Now)` * added support for collections: `print(Directory.GetFiles(".", "*"))` * Added decorateAutoClassAsCS6 setting for injection `using static dbg;` into auto-class decoration. * Issue#32: Inconsistent time stamp (.dll -vs- .pdb) when using `CSScript.CompileFile()` with 'debugBuild = true' * Added support for output file in //css_res. * Implemented supressing elevation during syntax checking (with `-check`) for the scripts with `//css_pre elevate` directive. * Improved settings file parsing to avoid throwing handled exceptions. * Added support for CSS_RESGEN environment variable for embedding resources with //css_res. * Code cleanup * Various obsolete code marked as error triggering. * Removed old obsolete ResolveSourceFileHandler delegate and MonoEvaluator.Configuration member. * Staretd removal of obsolete .NET1.1 code (conditional compiler directives).