Removed the shell/batch scripts and modified dub to be a stand-alone executable. ...

Also removed all implicit dependencies to vibe.d (such as always specifying the vibe.d source folder using -I).
Fixed expanding of packages with multiple package.json files (the top-level folder inside of the zip archive was detected wrongly).

Incomplete generation of VisualD project files. Missing: project dependencies being compilable libraries and precompiled libraries as well as system installed precompiled libraries.

Added missing file.