Change from "classic" TS 1.6 imports to the default resolution scheme.

- Use relative imports in place of most of our absolute ones.
- Add "private" ambient modules for modules that we need to import using
an absolute path (e.g. when app/.../test-something.ts needs to import
ui/styling/style-scope)

utils/utils.android.ts

@@ -1,4 +1,4 @@
-import common = require("utils/utils-common");
+import common = require("./utils-common");
 import trace = require("trace");
 
 global.moduleMerge(common, exports);
@@ -145,4 +145,4 @@ export function openUrl(location: string): boolean {
         return false;
     }
     return true;
-}
+}