Package.json rework

Moved .sh files into a scripts subdirectory (to eventually be replaced by npm scripts)

Moved tiddlywiki.js into a bin subdirectory (so it will be deployed as a `tiddlywiki` system command on install)

Revamped package.json - supersedes #99
 *  Added comments
 *  Added project and license URLs
 *  Added maintainers/contributors
 *  Added files/directory information for packagers
 *  Added scripts for `npm test`, `npm start`
 *  Mapped .sh files in scripts for `npm run-script 2bld` et al
 *  Added CommonJS spec implementation metadata
 *  Added semver-sync as a devDependency and express as an optionalDependency
 *  Added engine/os/cpu constraints for supported ("known good") platforms
 *  Added environment config block for deployments  (currently just server_port for `npm start` command)

Set up semver-sync versioning
 *  Maintains module version numbers in boot.js and bootprefix.js
 *  Maintains package.json version numbers for core
 *  Tested semver-sync bumping and tagging

Tested deployment scenarios with NPM
 *  development/production flags
 *  local/global install
 *  `npm link` install
 *  manual install with bundle