Speed up the build on Windows

The build of the project is entirely written in TypeScript. This requires compilation of the files once the build is started (npm start for instance).

There are significant slowdowns on windows which can be solved with pre-compilation:

cd angular2-seed
tsc --project tsconfig.json
npm start

Now each time you make a change in your build you'll have to run tsc --project tsconfig.json in order to reflect these changes.

Notice that inside tools will be generated files with extensions *.js and *.js.map, as well as files called gulpfile.js and gulpfile.js.map in the root of the seed. These files, by default, are ignored by git (take a look at .gitignore and tools/.gitignore).