try to fix closure compiler

Author: tinayuangao

scripts/closure-compiler/build-devapp-bundle.sh

@@ -12,15 +12,19 @@ cd $(dirname $0)/../..
 $(npm bin)/gulp build:devapp
 $(npm bin)/gulp :package:release
 
+echo 'Rebuild demo-app with ES2015 modules'
 # Rebuild demo-app with ES2015 modules. Closure compiler is then able to parse imports.
 $(npm bin)/tsc -p src/demo-app/tsconfig-build.json --target ES2015 --module ES2015
 
+echo 'Re-compile RxJS sources into ES2015'
 # Re-compile RxJS sources into ES2015. Otherwise closure compiler can't parse it properly.
 $(npm bin)/ngc -p scripts/closure-compiler/tsconfig-rxjs.json
 
+echo 'Create a list of all RxJS source files.'
 # Create a list of all RxJS source files.
 rxjsSourceFiles=$(find dist/packages/rxjs -name '*.js');
 
+echo 'exports to the different RxJS ES2015 files'
 # Due a Closure Compiler issue https://github.com/google/closure-compiler/issues/2247
 # we need to add exports to the different RxJS ES2015 files.
 for i in $rxjsSourceFiles; do