This PR addresses several issues and introduces some new features.

1. Angular5 support
2. Adds support for CSS files to be added through the css-loader for vanilla apps and the app.css (the nativescript-css-loader is now obsolete)
3. Adds the app.css in the snapshot for Android, it is registered in the vendor.js so the snapshot generator can load, and parse the NativeScript theme
4. Adds the PlatformFSPlugin to map files:
   • Filter alien files (e. g. when building for Android will filter .ios. files)
   • Rename platform specific files (e. g. when building for android *.android. will be renamed to *.)
   • Handles watching for platform specific files (e. g. for Android when watching for component.ts will also watch for component.android.ts)
5. Should bump the version to 0.9.0
6. Adds demo apps that feature most of the supported features in webpack and have automation tests on top
7. Adds the WatchStateLoggerPlugin to do IPC with the CLI and notify for watch state changes
8. Options! Webpack options are passed through the CLI with tns run ios|android --bundle --env.*
   • --env.snapshot enables snapshot for android
   • --env.uglify enables uglification and minification
   • --env.report creates the report folder with chunk stats
   • --env.aot for angular, enables the Angular ahead-of-time compilation

For Angular5

1. Implements a NativeScriptAngularCompilerPlugin that uses the new AngularCompilerPlugin from @angular/webpack
   The new AngularCompilerPlugin creates a TypeScript CompilerHost under the hood and uses it for webpack compiler.inputFileSystem and compiler.watchFileSystem, it also compiles CSS and HTML resources. The NativeScriptAngularCompilerPlugin extends the AngularCompilerPlugin to handle platform specific resource resolution and resolving compiler modules in the CompilerHost. Then the PlatformFSPlugin's effect is applied on top of the AngularCompilerPlugin's FS so webpack can work with the platform specific files seemlesly.
2. webpack --watch watch is able to recompile in under 2 sec, but is not yet integrated in the CLI

For JavaScript and TypeScript apps

1. Adds the PlatformFSPlugin
2. Enumerates the page.* files in the app folder and registers them in the NativeScript framework using dynamic webpack require contexts, it is then registered in the global.registerWebpackModule so the modules can load .js, .css, .sass, .xml, etc. files, dens no longer need to list these files manually

Breaking Changes

I am sorry guys, but the way this PR works makes a lot of sense (snapshotting the theme because we can, using the css-loader because we can, etc.) but that also introduces some annoying breaking changes:

• The theme should now be required using leading tilde without slash:
  @import '~nativescript-theme-core/css/core.light.css';.
  that's how the css-loader loads css files from the node_modules.
• The routes loadChildren best be absolute paths, System.import we use now has no support for referrer so the paths provided to loadChildren better be non-relative, so:
  loadChildren: "./details/ninja.module#NinjaModule" in the ninjas folder becomes:
  loadChildren: "~/ninjas/details/ninja.module#NinjaModule".
  in case you still want to use tns run ios|android without web pack.
• The tsconfig.json, for the love of tilde, better get paths like:

 "paths": {
 "~/*": [
 "app/*"
 ],
 "*": [
 "./node_modules/tns-core-modules/*",
 "./node_modules/*"
 ]
 }

• When bundled with webpack, webpack uses numbers for module.id and Angular throws number is not a string kind of errors. Replace all occurrences of moduleId: module.id with moduleId: __filename. This works well in {N} context, __filename is almost the same as module.id with the little difference that it has the .js extension, while webpack replaces occurrences of __filename with paths relative to the app folder.