rund: init at version 1.0.0

Adding a D Programming Language Compiler Wrapper tool that runs and caches D programs.  This is an alternative to the existing `rdmd` tool.  It's a rewrite that leverages a new compiler feature that allows it to run the compiler once instead of having to run it twice like `rdmd` does.  I decided to create a new tool rather than trying to support both older and new compilers in the same tool.  It also introduces new features like "Source Compiler Directives" which allow D Language source files to contain compiler configuration such as import paths, environment variables, etc.