refactor(compiler_cli): move it into modules/@angular and integrate properly into the build

This also does no more depend on a version
on npm for the compiler_cli.

Also runs the tests for tools/metadata

modules/@angular/compiler_cli/index.ts

@@ -0,0 +1,3 @@
+export {CodeGenerator} from './src/codegen';
+export {NodeReflectorHost} from './src/reflector_host';
+export {TsickleHost, MetadataWriterHost} from './src/compiler_host';