refactor(all): add index.ts, and build using es2015 and UMD bundles.

[hansl]

Similar to angular/angular.

As well:

• moved every @angular2-material/ZZZ/ZZZ to use the index
• moved every deep import from @angular2-material/core to the root of the package
• created an new tsconfig for spec files (since we won't compile spec files with umd because simpler)
• system config in lib has been renamed to system-config-spec because it's a spec-only file (one could say it's "spec-specific")
• now clean before running unittests, because it's safer.

The UMD bundles are rolled up to @angular2-material/XXX/XXX.umd.js while the es2015 are @angular2-material/XXX/index.js.

Packages have been updated.

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