Update superspawn 0.0.2 --> 0.1.0
Stores source of xtc installation in xtcfile.json. `xtc info` displays source of xtc installation.
xtc start executes project main script from xtc-0.8.0-beta8+. Add npm semver to dependencies.
Installing develop branch now uses URI for a tarball instead of git.

- Fixes 'invalid tar file" issue on Windows (something to do with npm cache)
- Was not installed as git repo anyway
Add `--production` option to all `npm install` calls. Can't hurt.
Call yo with explicit `xtc:app` arg instead of just `xtc`.
Install remaining project-level dependencies, e.g. hipsum.js. Print xtc-cli usage hints on installation completion.

- Run `npm install` on project after xtc install, generator-xtc install and project setup are complete.
Fix output of xtc post-install usage hints.