Add 'build' directory
Adding additional comments

Adding additional comments so that folks know to use the integration tool rather than copying this for better results.
Update Dart.gitignore

add the `.pub/` directory, and change the `packages` filter to match sub-folders.
Merge pull request #1205 from jlgrock/master

Adding additional comments
Merge pull request #1206 from devoncarew/patch-2

Update Dart.gitignore
Merge pull request #1198 from nicwortel/symfony-build

Add 'build' directory to Symfony.gitignore