* FIXED: Issue #3 incorrect -mode sys handling on Windows XP.

* FIXED: `Invalid switch - /B` in older xcopy. Part of issue #3.

* NEW: Implemented `-pkg-version` to set specific package version.

* NEW: Storing multiple versions in a packages folder.

* NEW: `pkg` and `system` mode aliases.

* NEW: `-global` key to use the global toolset instead of the local,
       like hMSBuild.

* CHANGED: Redirected warn messages into stderr stream.

* CHANGED: Default remote package 1.0.2 up to 1.0.3.
           To use the latest version, call `-pkg-version latest`