No more ambient modules for tns-core-modules/* subpackages.

- Use path mappings in tsconfig.json to resolve module typings
- Only use ambient mobules for global API's
- Move single-file modules to a subdir with the same name so that
we can provide a hand-written typing next to it (via package.json)
- Delete all mentions of tns-core-modules.d.ts
- Delete reference d.ts assembly build steps. Not needed anymore.
- HACK! Use a <reference> for global typings in application.d.ts
to avoid publishing a separate @types/tns-core-modules package.
- Rename declarations.d.ts to tns-core-modules.d.ts to preserve
JS project mappings in references.d.ts (the only place we use those)

tns-core-modules/css/package.json

@@ -31,5 +31,6 @@
     "stringifier",
     "stylesheet"
   ],
+  "types": "reworkcss.d.ts",
   "nativescript": {}
 }

tns-core-modules/css/reworkcss.d.ts

@@ -1,35 +1,33 @@
-declare module "css" {
-    export interface Position {
-        start: { line: number; column: number };
-        end: { line: number; column: number };
-    }
-
-    export interface Node {
-        type: "rule" | "keyframes" | "declaration" | "import";
-        position: Position;
-    }
-
-    export interface Declaration extends Node {
-        property: string;
-        value: string;
-    }
-
-    export interface Rule extends Node {
-        selectors: string[];
-        declarations: Node[];
-    }
-
-    export interface Keyframes extends Rule {
-        name: string;
-    }
-
-    export interface StyleSheet {
-        rules: Node[];
-    }
-
-    export interface SyntaxTree {
-        stylesheet: StyleSheet;
-    }
-
-    export function parse(css: string, options: any): SyntaxTree;
+export interface Position {
+    start: { line: number; column: number };
+    end: { line: number; column: number };
 }
+
+export interface Node {
+    type: "rule" | "keyframes" | "declaration" | "import";
+    position: Position;
+}
+
+export interface Declaration extends Node {
+    property: string;
+    value: string;
+}
+
+export interface Rule extends Node {
+    selectors: string[];
+    declarations: Node[];
+}
+
+export interface Keyframes extends Rule {
+    name: string;
+}
+
+export interface StyleSheet {
+    rules: Node[];
+}
+
+export interface SyntaxTree {
+    stylesheet: StyleSheet;
+}
+
+export function parse(css: string, options: any): SyntaxTree;