Enhancement

We should upgrade to TypeScript 2.6. The biggest impact is likely to be strictFunctionTypes which will be on by default when using strict.

• dojo/cli
• dojo/cli-build
• dojo/cli-create-app
• dojo/cli-create-widget
• dojo/cli-export-project
• dojo/cli-test-intern
• dojo/core
• dojo/has
• dojo/i18n
• dojo/interfaces
• dojo/interop
• dojo/loader
• dojo/routing
• dojo/shim
• dojo/stores
• dojo/streams
• dojo/widget-core
• dojo/widgets
• dojo/dojo2-package-template
• dojo/grunt-dojo2
• dojo/grunt-dojo2-extras
• dojo/test-extras
• dojo/web-editor
• dojo/webpack-contrib